Access profile

Given the multidisciplinary nature of the scientific field of the programme, there are a wide range of degrees that qualify applicants for admission. The applicants considered most suitable for admission to the doctoral programme in Materials Science and Engineering are bachelor’s degree holders with a scientific and technological background who have completed a master's degree in Materials Science and Advanced Materials Engineering or a related field.

In addition to having suitable academic qualifications, it is considered important that applicants have certain personal characteristics – namely, an interest in the research projects carried out within the framework of the programme; critical and analytical skills; initiative, perseverance and persistence in their academic work; the ability to work in a team; and the ability to communicate effectively in English, both orally and in writing.

The main entrance qualifications for the programme are as follows:

Bachelor’s degree in Engineering or higher engineering degree (Industrial, Materials or Chemical Engineering) or a pre-EHEA degree in Physical and/or Chemical Sciences with a master’s degree in Materials Science and Engineering (or proof of having completed 60 ECTS credits of this master’s degree), or another master’s degree with the same content, from any higher education institution in the EHEA, or a non-EHEA country if the applicant is eligible for admission to doctoral studies in that country.

Students with the following qualifications are eligible for direct admission:

Bachelor’s degree in Engineering (Industrial, Materials, Chemical or similar) or a pre-EHEA degree in Physics and/or Chemistry with a master’s degree in Materials Science and Engineering.

With bridging courses:

Holders of a bachelor’s degree in Engineering (Industrial, Materials, Chemical or similar) or a pre-EHEA degree in Physics and/or Chemistry who have completed a master's degree in a field other than Materials Science and Engineering. If admitted, these students will be required to take bridging courses carrying up to 60 ECTS credits (subjects of the master’s degree that they have not taken).

Output profile

Doctoral candidates who complete a doctoral degree will have acquired the following competencies, which are needed to carry out quality research (Royal Decree 99/2011, of 28 January, which regulates official doctoral studies):

a) A systematic understanding of the field of study and a mastery of the research skills and methods related to the field.
b) An ability to conceive, design or create, put into practice and adopt a substantial process of research or creation.
c) An ability to contribute to pushing back the frontiers of knowledge through original research.
d) A capacity for critical analysis and an ability to assess and summarise new and complex ideas.
e) An ability to communicate with the academic and scientific community and with society in general as regards their fields of knowledge in the manner and languages that are typical of the international scientific community to which they belong.
f) An ability to foster scientific, technological, social, artistic and cultural progress in academic and professional contexts within a knowledge-based society.

The award of a doctoral degree must equip the graduate for work in a variety of settings, especially those requiring creativity and innovation. Doctoral graduates must have at least acquired the personal skills needed to:

a) Develop in contexts in which there is little specific information.
b) Find the key questions that must be answered to solve a complex problem.
c) Design, create, develop and undertake original, innovative projects in their field.
d) Work as part of a team and independently in an international or multidisciplinary context.
e) Integrate knowledge, deal with complexity and make judgements with limited information.
f) Offer criticism on and intellectually defend solutions.

Number of places

15

Duration of studies and dedication regime

Duration
The maximum period of study for full-time doctoral studies is three years, counted from the date of admission to the programme to the date of submission of the doctoral thesis. The academic committee of the doctoral programme may authorise a doctoral candidate to pursue doctoral studies on a part-time basis. In this case, the maximum period of study is five years, counting from the date of admission to the programme to the date of submission of the doctoral thesis. For calculating these periods, the date of admission is considered to be the date of the first enrolment for tutorials, and the date of submission the moment in which the Doctoral School officially deposits the doctoral thesis.

For full-time doctoral candidates, the minimum period of study is two years, counted from the date of an applicant's admission to the programme until the date on which the doctoral thesis is deposited; for part-time doctoral candidates it is four years. When there are justified grounds for doing so, and the thesis supervisor and academic tutor have given their authorisation, doctoral candidates may request that the academic committee of their doctoral programme exempt them from the minimum period of study requirement.

The calculation of periods of study will not include periods of absence due to illness, pregnancy or any other reason provided for in the regulations in force. Students who find themselves in any of these circumstances must notify the academic committee of the doctoral programme, which, where appropriate, must inform the Doctoral School. Doctoral candidates may also temporarily withdraw from the programme for up to one year, and this period may be extended for an additional year. Doctoral candidates who wish to interrupt their studies must submit a justified request to the academic committee of the doctoral programme, which will decide whether or not to approve the request. Each programme will establish conditions for readmission to doctoral studies.

Extension
If full-time doctoral candidates have not applied to deposit their thesis by the end of the three-year period of study, the academic committee of the programme may authorise an extension of up to one year. In exceptional circumstances, a further one-year extension may be granted, subject to the conditions established by the corresponding doctoral programme. In the case of part-time doctoral candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

Dismissal from the doctoral programme
A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

Enrollment aid

The programme does not provide any specific grants to cover enrolment fees. In exceptional cases, research groups may offer one-off grants.

Organization

• Maspoch Ruldua, Maria Lluïsa

• Arencon Osuna, David
• De La Cruz Jesús, Lucía Guadalupe
• Jimenez Pique, Emilio
• Mas Moruno, Carlos
• Maspoch Ruldua, Maria Lluïsa
• Perez Campdepadros, Irene

• Department of Materials Science and Metallurgy (PROMOTORA)

Diagonal-Besòs Campus Management and Support Unit
Building A
Av. Eduard Maristany, 16
08019 Barcelona

Tel: (+34) 934 011 792

Agreements with other institutions

Access profile

Given the multidisciplinary nature of the scientific field of the programme, there are a wide range of degrees that qualify applicants for admission. The applicants considered most suitable for admission to the doctoral programme in Materials Science and Engineering are bachelor’s degree holders with a scientific and technological background who have completed a master's degree in Materials Science and Advanced Materials Engineering or a related field.

In addition to having suitable academic qualifications, it is considered important that applicants have certain personal characteristics – namely, an interest in the research projects carried out within the framework of the programme; critical and analytical skills; initiative, perseverance and persistence in their academic work; the ability to work in a team; and the ability to communicate effectively in English, both orally and in writing.

The main entrance qualifications for the programme are as follows:

Bachelor’s degree in Engineering or higher engineering degree (Industrial, Materials or Chemical Engineering) or a pre-EHEA degree in Physical and/or Chemical Sciences with a master’s degree in Materials Science and Engineering (or proof of having completed 60 ECTS credits of this master’s degree), or another master’s degree with the same content, from any higher education institution in the EHEA, or a non-EHEA country if the applicant is eligible for admission to doctoral studies in that country.

Students with the following qualifications are eligible for direct admission:

Bachelor’s degree in Engineering (Industrial, Materials, Chemical or similar) or a pre-EHEA degree in Physics and/or Chemistry with a master’s degree in Materials Science and Engineering.

With bridging courses:

Holders of a bachelor’s degree in Engineering (Industrial, Materials, Chemical or similar) or a pre-EHEA degree in Physics and/or Chemistry who have completed a master's degree in a field other than Materials Science and Engineering. If admitted, these students will be required to take bridging courses carrying up to 60 ECTS credits (subjects of the master’s degree that they have not taken).

Access requirements

Applicants must hold a Spanish bachelor’s degree or equivalent and a Spanish master’s degree or equivalent, provided they have completed a minimum of 300 ECTS credits on the two degrees (Royal Decree 43/2015, of 2 February)

In addition, the following may apply:

• Holders of an official degree awarded by a university in Spain or any other country in the European Higher Education Area, pursuant to the provisions of Article 16 of Royal Decree 1393/2007, of 29 October, which establishes official university course regulations, who have completed a minimum of 300 ECTS credits on official university degrees, of which at least 60 must be at the master's degree level.
• Holders of an official Spanish bachelor’s degree comprising at least 300 credits, as provided for by EU regulations. Holder of degrees of this kind must complete bridging courses unless the curriculum of the bachelor’s degree in question included research training credits equivalent in value to those which would be earned on a master's degree.
• Holders of an official university qualification who, having passed the entrance examination for specialised medical training, have completed at least two years of a training course leading to an official degree in a health-sciences specialisation.
• Holders of a degree issued under a foreign education system. In these cases, homologation is not required, but the UPC must verify that the degree certifies a level of training equivalent to an official Spanish master's degree and qualifies the holder for admission to doctoral studies in the country where it was issued. Admission on this basis does not imply homologation of the foreign degree or its recognition for any purpose other than admission to doctoral studies.
• Holders of a Spanish doctoral qualification issued under previous university regulations.

Note 1: Doctoral studies entrance regulations for holders of an undergraduate degree awarded before the introduction of the EHEA (CG 47/02 2014)

Note 2: Governing Council Decision 64/2014, which approves the procedure and criteria for assessing the fulfilment of academic admission requirements for doctoral studies by holders of non-homologated foreign degrees (CG 25/03 2014)

Admission criteria and merits assessment

Weighting of admission criteria:

Training complements

Enrolment period for new doctoral students

The ordinary enrolment period starts in September and ends on 15 October of each academic year, though the enrolment date will depend on the admission decision.

More information at the registration section for new doctoral students

Enrolment period

The enrolment period will be from 15 September to 15 October of each academic year.

More information at the general registration section

Procedure for the preparation and defense of the research plan

Doctoral candidates must submit a research plan, which will be included in their doctoral student activity report, before the end of the first year. The plan may be improved over the course of the doctoral degree. It must be endorsed by the tutor and the supervisor, and it must include the method that is to be followed and the aims of the research.

At least one of these annual assessments will include a public presentation and defence of the research plan and work done before a committee composed of three doctoral degree holders, which will be conducted in the manner determined by each academic committee. The examination committee awards a Pass or Fail mark. A Pass mark is a prerequisite for continuing on the doctoral programme. Doctoral candidates awarded a Fail mark must submit a new research plan for assessment by the academic committee of the doctoral programme within six months.

The committee assesses the research plan every year, in addition to all of the other activities in the doctoral student activity report. Doctoral candidates who are awarded two consecutive Fail marks for the research plan will be obliged to definitely withdraw from the programme.

If they change the subject of their thesis, they must submit a new research plan.

Formation activities

Activity: Preparation and initial defence of research plan.
Hours: 4.
Type: compulsory

Activity: Programme-specific courses, seminars and workshops.
Hours: 15.
Type: compulsory

Activity: Programme-specific courses, seminars and workshops.
Hours: 40.
Type: optional

Activity: Complementary courses and seminars given by visiting professors.
Hours: 12.
Type: optional

Activity: Publications
Hours: 100.
Type: optional

Activity: Research stays.
Hours: 480.
Type: optional

Activity: Cross-disciplinary activities.
Hours: 15.
Type: compulsory

Activity: Cross-disciplinary activities.
Hours: 30.
Type: optional

Procedure for assignment of tutor and thesis director

The academic committee of the doctoral programme assigns a thesis supervisor to each doctoral candidate when they are admitted or enrol for the first time, taking account of the thesis supervision commitment referred to in the admission decision.

The thesis supervisor will ensure that training activities carried out by the doctoral candidate are coherent and suitable, and that the topic of the candidate’s doctoral thesis will have an impact and make a novel contribution to knowledge in the relevant field. The thesis supervisor will also guide the doctoral candidate in planning the thesis and, if necessary, tailoring it to any other projects or activities undertaken. The thesis supervisor will generally be a UPC professor or researcher who holds a doctoral degree and has documented research experience. This includes PhD-holding staff at associated schools (as determined by the Governing Council) and UPC-affiliated research institutes (in accordance with corresponding collaboration and affiliation agreements). When thesis supervisors are UPC staff members, they also act as the doctoral candidate’s tutor.

PhD holders who do not meet these criteria (as a result of their contractual relationship or the nature of the institution to which they are attached) must be approved by the UPC Doctoral School's Standing Committee in order to participate in a doctoral programme as researchers with documented research experience.

The academic committee of the doctoral programme may approve the appointment of a PhD-holding expert who is not a UPC staff member as a candidate’s thesis supervisor. In such cases, the prior authorisation of the UPC Doctoral School's Standing Committee is required. A UPC staff member who holds a doctoral degree and has documented research experience must also be proposed to act as a co-supervisor, or as the doctoral candidate’s tutor if one has not been assigned.

A thesis supervisor may step down from this role if there are justified reasons (recognised as valid by the committee) for doing so. If this occurs, the academic committee of the doctoral programme will assign the doctoral candidate a new thesis supervisor.

Provided there are justified reasons for doing so, and after hearing any relevant input from the doctoral candidate, the academic committee of the doctoral programme may assign a new thesis supervisor at any time during the period of doctoral study.

If there are academic reasons for doing so (an interdisciplinary topic, joint or international programmes, etc.) and the academic committee of the programme gives its approval, an additional thesis supervisor may be assigned. Supervisors and co-supervisors have the same responsibilities and academic recognition.

The maximum number of supervisors of a doctoral thesis is two: a supervisor and a co-supervisor.

For theses carried out under a cotutelle agreement or as part of an Industrial Doctorate, if necessary and if the agreement foresees it this maximum number of supervisors may not apply. This notwithstanding, the maximum number of supervisors belonging to the UPC is two.

More information at the PhD theses section

Permanence

The academic committee of the programme may authorise an extension of up to one year for full-time doctoral candidates who have not applied to deposit their thesis by the end of the three-year period of study, in the terms outlined in the Academic Regulations for Doctoral Studies of the Universitat Politècnica de Catalunya. In the case of part-time candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

International Mention

The doctoral degree certificate may include International Doctorate mention. In this case, the doctoral candidate must meet the following requirements:

a) During the period of study leading to the award of the doctoral degree, the doctoral candidate must have spent at least three months at a respected higher education institution or research centre outside Spain to complete courses or do research work. The stays and activities carried out must be endorsed by the thesis supervisor and authorised by the academic committee of the programme. The candidate must provide a certifying document issued by the person responsible for the research group of the body or bodies where the stay or activity was completed. This information will be added to the doctoral student’s activity report.
b) Part of the thesis (at least the summary and conclusions) must be written and presented in one of the languages commonly used for science communication in the relevant field of knowledge, which must not be an official language of Spain. This rule does not apply to stays and reports in Spanish or to experts from Spanish-speaking countries.
c) At least two PhD-holding experts belonging to a higher education institution or research centre outside Spain must have issued officially certified reports on the thesis.
d) The thesis examination committee must have included at least one PhD-holding expert from a higher education or research institution outside Spain who was not responsible for the candidate’s stay abroad (point a) above).
e) The thesis defence must have taken place on UPC premises or, in the case of joint programmes, at the location specified in the collaboration agreement.

List of authorized thesis for defense

Last update: 16/10/2021 04:47:07.

List of lodged theses

Last update: 16/10/2021 04:30:36.

List of defended theses by year

• BESHARATLOO, HOSSEIN: Micromechanical properties of inorganic multiphase materials
  
  Author: BESHARATLOO, HOSSEIN
  Thesis link: http://hdl.handle.net/10803/672145
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Article-based thesis
  Reading date: 13/05/2021
  Thesis director: LLANES PITARCH, LUIS MIGUEL | ROA ROVIRA, JOAN JOSEP
  

  Committee:
       PRESIDENT: RINALDI, ANTONIO
       SECRETARI: JIMENEZ PIQUÉ, EMILIO
       VOCAL: MSAOUBI, RACHID
  Thesis abstract: This thesis is dedicated to understanding the micromechanical properties of multiphase materials which are indispensable in today¿s engineering applications. The mechanical behavior of these materials is dictated by the intrinsic response of each constitutive phase as well as the fashion in which they interact with each other. Therefore, an accurate assessment of both microstructural characteristics and small-scale mechanical properties becomes key for understanding the macroscopic behavior of these materials.Within the above context, the current study is intended to offer a systematic investigation, aiming to assess small-scale mechanical properties of multiphase materials through a protocol based on massive nanoindentation and statistical analysis. It consists of three sequential stages: (1) microstructural characterization, (2) micromechanical evaluation (massive indentation and statistical analysis), (3) correlation between microstructure and mechanical properties using advanced characterization techniques.Microstructural characterization of studied systems was carried out through extensive field emission scanning electron microscopy analysis. This is an essential step for determining testing parameters to be used when implementing massive indentation, particularly penetration depth of performed imprints. Based on the acquired information, massive indentation testing and statistical analysis of experimentally gathered data were implemented to determine the local properties of several unidentified phases. Such data analysis was then complemented by the use of different advanced characterization techniques for deeper inspection of microstructural features. Main goal of this final step was to define the unidentified mechanically distinct phases, based on physically- based correlations between microstructure features and small-scale properties.The proposed and described protocol has been implemented on three different materials: Duplex Stainless Steels (DSS), Polycrystalline cubic Boron Nitride (PcBN) composite and Ti(C,N)-FeNi cermets. They are representative of metal-metal, ceramic- ceramic, and ceramic-metal systems, respectively.Regarding DSS, the influence of the processing route on the local mechanical properties (hardness (H) and elastic modulus (E)) of ¿ and a phases of a DSS was successfully evaluated. Moreover, a novel 2D histogram of hardness and elastic modulus was introduced and validated as an effective tool to correlate microstructure and intrinsic mechanical properties of the constitutive phases of DSSs.PcBN composite consists of cBN particles embedded within a TiN binder. The correlation of relative B/N ratio and local hardness for individual cBN particles was studied, through complementary analysis using electron probe X-ray microanalysis of the data attained using the proposed methodology.The influence of ceramic/metal phase ratio and C addition on the local hardness of Ti(C,N)¿FeNi cermets have been assessed. Regarding the small-scale properties of the constitutive phases, the intrinsic hardness of both Ti(C,N) particles and FeNi binder were determined using the suggested testing procedure.It has been proven that the proposed methodology can be considered as a successful testing protocol for determining small-scale mechanical properties (H and E) of the studied multiphase systems. Nevertheless, successful implementation requires careful consideration of testing parameters used, based on microstructural, residual imprint, and plastic flow length scales.
  

• FRÓMETA GUTIÉRREZ, DAVID: On the measurement of fracture toughness to understand the cracking resistance of Advanced High Strength Steel sheets
  
  Author: FRÓMETA GUTIÉRREZ, DAVID
  Thesis link: http://hdl.handle.net/10803/672379
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Article-based thesis
  Reading date: 28/01/2021
  Thesis director: CASELLAS PADRO, DANIEL | CALVO MUÑOZ, JESSICA
  

  Committee:
       PRESIDENT: KAJBERG, JÖRGEN
       SECRETARI: FARGAS RIBAS, GEMMA
       VOCAL: PARDOEN, THOMAS
  Thesis abstract: Automotive designers are constantly facing new challenges to meet the more and more stringent safety and CO2 emission legislations. Concerning the latter, vehicle lightweighting has become one of the main goals of the automotive industry, not only to reduce fuel consumption in fuel-powered cars but also to enhance the battery range in electric vehicles. At the same time, weight reduction cannot be attained at the expense of passenger¿s safety in case of a crash. Hence, it is important to select the best-suited strategies to find the optimum balance between weight reduction and crashworthiness. In this sense, Advanced High Strength Steels (AHSS) have been positioned as one of the most effective solutions to this demand. AHSS present very high strength and high crash performance, which allows reducing vehicle mass while maintaining the safety of the occupants. These outstanding mechanical properties have promoted their widespread implementation for structural and crash-relevant automobile components. However, the application of AHSS have introduced new challenges related to their limited ductility and cracking resistance. Premature cracking during edge forming operations (edge cracking) or the occurrence and propagation of cracks under impact loading are some of the common cracking related issues in processing and implementation of AHSS.To face these problems, the development of new approaches to properly characterize the cracking resistance of AHSS has become unavoidable since conventional failure criteria based on uniaxial tensile properties and forming limit curves fail to describe cracking related phenomena. In this thesis, a fracture mechanics-based approach is proposed to rationalize and understand the crack initiation and propagation resistance of AHSS. Results have been correlated with edge cracking resistance and crash behaviour of a broad range of advanced high strength sheet steels.Fracture toughness is evaluated in the frame of fracture mechanics through different testing methods, such as the essential work of fracture, the J-integral and the Kahn-type tear tests. The relationship between the obtained fracture toughness parameters as well as the limitations of the different methods have been discussed. High-resolution video extensometry and Digital Image Correlation (DIC) techniques were used to investigate the fracture behaviour of the different steels. Edge cracking resistance is characterized by standard hole expansion tests and DIC-assisted hole tension tests. Crashworthiness is assessed through laboratory impact resistance tests. The influence of microstructural constituents on the crack propagation resistance of AHSS is also assessed.The results show that fracture toughness, in particular the specific essential work of fracture (we), is a suitable material property to understand the cracking behaviour of AHSS and rank the material¿s resistance to different crack-related failures, such as edge fracture or crack propagation during a crash event. These conclusions are based on the good correlation established between we and the results from edge cracking and impact resistance tests. On the other hand, the experimental observations show that we can be used to discern the role of microstructural constituents on the fracture behaviour of AHSS.It is pointed out that proper microstructural design cannot be only focused on tensile properties since they do not inform about cracking resistance.According to all the experimental findings, the fracture toughness is considered as a relevant material property for AHSS design and performance classification. In line with this, a new classification system, considering global ductility and fracture toughness, is proposed for a more comprehensive description of the overall formability and fracture behaviour of AHSS.
  

• GAMONAL REPISO, PABLO: Perceived quality characterization of micro-textured injection moulded components for automotive interior applications
  
  Author: GAMONAL REPISO, PABLO
  Thesis link: http://hdl.handle.net/10803/672315
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Normal
  Reading date: 22/07/2021
  Thesis director: MASPOCH RULDUA, MARIA LLUÏSA | SANCHEZ SOTO, MIGUEL ANGEL
  

  Committee:
       PRESIDENT: BALART GIMENO, RAFAEL ANTONIO
       SECRETARI: SANTANA PEREZ, ORLANDO ONOFRE
       VOCAL: FERNÁNDEZ RENNA, ANA INÉS
  Thesis abstract: The present PhD thesis is framed within a collaborative project in which institutions such as the Universitat Politècnica de Catalunya Barcelona-Tech, the Centre Català del Plàstic and SEAT S.A have participated. The main objective of this research is to improve the surface quality of the textured injection moulded components of the car interior. To this end, a methodology that allows assessing the appearance objectively using three-dimensional characterization techniques is proposed.The texture replication ratio of a mould cavity was first investigated. Squared samples of Polypropylene (PP) were injection moulded. It was found that the holding pressure was the most significant parameter for improving the texture replication ratio. In addition, using three-dimensional characterization techniques, it was demonstrated that the multi-scale methodology was a suitable technique to quantify the replication ratio and effectively separate the main surface components namely, roughness, waviness and form either at the macro- or the micro-scale. Four texture types were utilized to measure the surface appearance. The first one was a leather texture, the second and the third types were obtained by applying a mould treatment on the previous original leather texture. The fourth one was obtained through a painting process. The appearance was measured using a new Total Appearance Measurement (TAM) apparatus. A relationship between topographic features such as roughness, functional height distribution (FHD), texture slope (TS) and texture aperture angle (TAA) and surface appearance properties such as gloss and reflectivity contrast was established. Finally, the surface performance was studied by means of both scratch and mar resistance tests. The texture influence on the scratch hardness and the scratch visibility resistance was evaluated and quantified using three dimensional techniques. Topographic characteristics such as peak-to-valley symmetry and the number of micro-asperities were analysed. The results showed that surfaces with higher symmetry in their functional height distributions yield lower lightness variations (L*) between the scratch pattern and its residual background height (RBH). On the other hand, topographies with a smaller number of micro-asperities on top of the texture provided an enhanced mar resistance. In these cases, deformation mechanisms such as ironing are minimized, resulting in a lower gloss variation and lower contrast between the damaged area and its surroundings.
  

• KAMRANI MOGHADAM, MOHAMMAD REZA: Preparation and characterization of reactive extrusion modified PLA/ABS blends and its foams
  
  Author: KAMRANI MOGHADAM, MOHAMMAD REZA
  Thesis link: http://hdl.handle.net/10803/672320
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Normal
  Reading date: 21/07/2021
  Thesis director: SANCHEZ SOTO, MIGUEL ANGEL | CAILLOUX, JONATHAN
  

  Committee:
       PRESIDENT: LÓPEZ MARTÍNEZ, JUAN
       SECRETARI: MASPOCH RULDUA, MARIA LLUÏSA
       VOCAL: CASTILLO LÓPEZ, GERMAN
  Thesis abstract: The current thesis takes place within the context of the projects MAT2016-80045-R "Aplicaciones industriales de compuestos y mezclas basados en REX-PLA" and the project "PLAIABS Blends: Recydability and weight reduction" financially supported by the Ministerio de Economía y Competitividad of the Spanis h Government and SEAT res pectively.The main objective was to improve the properties of poly lactic acid (PLA) in arder to make it suitable for long-lasting applications where emphasis is de\Qted to the reduction of carbon dioxide emissions and the renewable raw materiaIs content. Among the different routes to enhance PLA properties, blending was used, as it is easily scalable bythe industry. Dueto its good balance of properties, ABS was considered a suitable polymer to be used together with PLA However, dueto their immiscibili ty, a coupling agent (ABS-g -MAH) was introduced.Apart of brittl ness, another PLA problem is its relatively easy degradation during process ing. Previous studies of the Group indicated that PLAdegradation could be limited using a multi epoxide reactive agent that a110ids the loss in molecular weight and increases the PLA melt visc osity, which, on the other hand, facilitates processing . Moreover, it was believed that the unreacted chain extender epoxide groups could also form covalent bonding with the coupling agent improving ABS and PLA compatibility.Using foams both the total weight and carbon dioxide generation of components can be diminished. For these reasons, different techniques for physicallyfoaming the blends either during injection (MuCell) or through a batch process were object of research. The effect of the above mentioned chain extender and the effect of a tale filler on the batch-foaming behavior of PLAwas studied.The first step of the research consisted in obtained the base materiaIs by reactive extrusion (REX) at a pilot plant seale (50 kg.). A conventional injection molding process was then employed to obtain standard samples that were used for the thermo­ mechanical characterization ofthe blends.The thermal stabilitywas studied bythe Kissinger 's method. The results showed that it was improved when the amount of ABS-g-MAH was increased. From the DSC analysis, it was found that in comparison to more perfect REX-PLA structures, crystals with a smaller lamellar thickness were formed in the blends. The differences in crystallinitywere small and do not influence the mechanical properties. The presence of ABS in the compositions led to a decrease ofthe blend 's storage modulus. Nonetheless, the ABS phase was found to playthe role of scaffold for the PLA phase that can undergo re­ crystallization, being thus able to support a certain amount of loading during heating.The physical foaming ofthe different injected blends was difficult to be achieved. The optimization ofthe foaming conditions required several triaIs and a large quantityof material. As the amount of each blend was limited, only a partial number of the proposed experiments were possible. The obtained blends contained a few large cells as well as a certain population of small sized cells. Although a complete micro-cellular structure was not achieved, the obtained one was similar to that of previous works found in literature. lt was, however, demonstrated that this technique can be used byindustryto generate lighter components.Batch foaming using CO2 in supercritical conditions resulted in successful foams with cell sizes below 100 microns and very high cell densi ties. In comparison to PLA, dueto its higher viscosity and melt resistance, using REX-PLA resulted in improved level offoaming which prevents from cell coalescence and collapse. The presence of ABS in the blends allowed broadening the range of pressure and temperatures in which foams can be produced. Tale was found to actas a nucleating agent leading to smaller cell sizes and higher cell densities in the foamed blends.
  

• MINGUELA DÍAZ, JOAQUIM: Surface characterization and cell instructive properties of superficially modified dental zirconia
  
  Author: MINGUELA DÍAZ, JOAQUIM
  Thesis link: http://hdl.handle.net/10803/672324
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Article-based thesis
  Reading date: 21/07/2021
  Thesis director: MAS MORUNO, CARLOS | ROA ROVIRA, JOAN JOSEP
  

  Committee:
       PRESIDENT: SEGARRA RUBÍ, MERCÈ
       SECRETARI: ESPAÑOL PONS, MONTSERRAT
       VOCAL: SUÁREZ VALLEJO, SEBASTIÁN
  Thesis abstract: Tetragonal polycrystalline zirconia doped with 3 mol% yttria (3Y-TZP) has become one of the most popular dental ceramics. Thanks to its outstanding mechanical properties (including high hardness. Toughness and wear resistance).Biocompatibility and white color. It is now commonly employed to produce components such as crowns, implants, abutments, bridges or posts and cores.In the case of dental implants, which are directly screwed into the jawbone, implant's surfaces can be modified through different physical or chemical techniques to ensure a rapid and proper osteointegration. In the first case, surface topography is known to play a critica! role in cell-material interactions and to influence several cell functions such as adhesion, proliferation or differentiation. In the second case, specific chemical cues such as integrin-binding peptidic molecules from bone extracellular matrix can affect cell behavior with a high degree of specificity. The combination of both strategies may provide a powerful tool to obtain an improved bone-to-implant contact and ensure long lasting implants.In this Ph.D. Thesis a dual approach employing surface topographical modification and peptidic biofunctionalization on dental zirconia is explored, with the aim of providing a flexible tool to improve tissue integration of ceramic restorations.Regarding surface topographical modifications, two different strategies are investigated: grinding and laser-micropatterning. Both of them can generate not only rough surfaces at the micro- and submicrometric length scale but also other features such as grooves, which may guide cell growth. However, these two techniques are based on different principies. While in grinding technique the material is removed by a mechanical process, laser patterning is based on the thermal effects of absorbed photons.However, these methods are not exempt from introducing a certain degree of surface damage, which can be detrimental for the final application. In addition, 3Y-TZP is susceptible of a spontaneous surface phase transformation from tetragonal (t-) to monoclinic (m-) phase under two different scenariu . One is known as transformation toughening and it is a stress-assisted mechanism accompanied by a volume increase (4%) activated by the near tip crack stress field, which increase crack propagation resistance. On the other hand, a second scenario exists known as low temperature degradation (LTD). In this case, aging by progressive t- to m- transformation at the surface is triggered by water molecules. In this particular case, this mechanism induces roughening and micro-cracking, which can drastically reduce the mechanical properties and in particular the wear resistance by generating pull-out of 3Y-TZP grains. In this regard, sorne surface treatments can affect the LTD resistance of the material, or even induce this phase transformation. Far these reasons, a particular emphasis is placed on the changes in the surface and subsurface introduced by both methods. Damage, microstructure, phase transformation and residual stresses are characterized, as well as its effects on LTD and mechanical properties.On the other hand, peptidic biofunctionalization is carried out by using a peptidic platform that incorporates the cell-adhesive RGD and the osteogenic DWIVA motives. This strategy is combined with the best performing topography-modifying treatment. On this surface that integrales the stimuli provided by topography and the peptides, cell adhesion, cell migration and osteogenic properties are characterized in detail.
  

• RAYMOND LLORENS, SANTIAGO: Biomimetic Bone Grafts: from the lab to the clinic
  
  Author: RAYMOND LLORENS, SANTIAGO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Temporary seizure
  Reading date: 13/09/2021
  Thesis director: GINEBRA MOLINS, MARIA PAU
  

  Committee:
       PRESIDENT: LEVATO, RICCARDO
       SECRETARI: LABAY, CEDRIC PIERRE
       VOCAL: CABALLÉ SERRANO, JORDI
  Thesis abstract: Bone grafting is a common medical practice in today¿s society, being bone the second most transplanted tissue worldwide after blood. Therefore, it represents a field of major interest for both, biomedical research and the biomedical industry. Despite the ability of bone to self-heal, in some scenarios where defects are large or complex, bone grafts are essential for a successfully regeneration. Although autografting is still today the gold standard in terms of biological performance, the limited availability and morbidity associated with this practice drive to search for alternatives. Synthetic grafts arise as a promising option due to their unlimited availability and the possibility to tune their structure and composition for optimal performance.The present thesis explores biomimetic calcium deficient hydroxyapatite (CDHA), a promising material for synthetic bone grafts, in a translational-oriented perspective. Two product presentations are studied: A more conventional granulated conformation and a 3D printed personalised format.Chapter 1 offers a brief overview of bone biology, as well as a state of the art of the currently available bone grafting strategies found in the literature. Chapter 2 focuses on the validation of the in vivo performance of CDHA granules compared to the well- established bovine xenograft particulate grafts in a dental indication in miniature swine. It is concluded that both biomaterials meet the requirements for bone grafting, (i.e., biocompatibility, osseointegration, and osteoconduction). Moreover, it is revealed that granule morphology is a key factor to ensure the preservation of the grafted volume. In the following chapters, the focus is moved to the 3D printed personalised CDHA bone grafts. Chapter 3 investigates different approaches to accelerate the consolidation process of the 3D printed grafts in order to make the technology more suitable for industrial applications, and develops a hydrothermal treatment that reduces the reaction time to 30 minutes instead of the 7 days needed in the biomimetic approach. Despite the slight differences in physicochemical properties associated to this approach (e.g., microstructure, crystalline phase, microporosity, specific surface area), the resulting scaffolds support adhesion and proliferation of rat mesenchymal stem cells, suggesting its potential as bone graft substitutes. In Chapter 4 the hydrothermal route introduced in the previous chapter is compared to the long-established biomimetic treatment in terms of the in vivo performance of the 3D-printed scaffolds through orthotopic implantation in rabbit condyle monocortical defects. The samples treated with this new process, in addition to the excellent biocompatibility, osseointegrative and osteoconductive properties characteristic of biomimetic CDHA, exhibit a significantly higher amount of newly formed bone than the biomimetic counterpart. This enhanced performance is attributed to the higher permeability of the microstructure, as demonstrated with a protein adsorption test. Chapter 5 explores a strategy to enhance the degree of concavity and specific surface area of 3D printed structures obtained by microextrusion, by using nozzles with non-circular cross-sections. Besides achieving the intended purpose and characterising the 3D-printed structures, different technical constraints for the printing process associated to the use of non-circular nozzles are identified. In a further step, this developed technology is applied to the fabrication of 3D-printed bone grafts with concave filament surfaces and tested in vivo in a rabbit condyle orthotopic model in Chapter 6. It is found that using strands with star-shaped cross-sections helps to guide bone, enhancing the osteoconductive properties of the scaffolds. Finally, Chapter 7 summarises all the work carried out in this thesis to transfer the 3D printing technology of synthetic bone grafts to the market, turning it into a commercially available product
  

• SÁNCHEZ ARTIGAS, MARINA: Caracterización de la unión vidrio-metal en la tecnología Glass to Metal Seal y el estudio de nuevos materiales y procesos de fabricación
  
  Author: SÁNCHEZ ARTIGAS, MARINA
  Thesis link: http://hdl.handle.net/10803/670881
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Confidentiality
  Reading date: 17/02/2021
  Thesis director: CABRERA MARRERO, JOSE MARIA | PICAS BARRACHINA, JOSEP ANTON
  

  Committee:
       PRESIDENT: FERRARI FERNÁNDEZ, BEGOÑA
       SECRETARI: CALVO MUÑOZ, JESSICA
       VOCAL: BAILE PUIG, MARIA TERESA
       VOCAL: LLORCA ISERN, NURIA
       VOCAL: COLOMINAS GUARDIA, CARLES
  Thesis abstract: This doctoral thesis has been carried out at the company VAC-TRON S.A., together with the Department of Materials Science and Engineering of Universitat Politècnica de Catalunya, in the Besós (EEBE) and Vilanova i la Geltrú (EPSEVG) campus, with the support of the Industrial Doctorate Plan of the Secretariat for Universities and Research of the Department of Business and Knowledge of the Generalitat de Catalunya. The scientific and technological interest that justifies this research line answers the concern to know, characterize and improve the products manufactured by glass to metal seal, achieving a knowledge scientifically based that allows optimizing the current way of working in the company.The technology of glass-metal sealing consists of the manufacture of hermetic components, composed of a metal base, a glass preform and metal pins, which are joined by heating the glass to practically a melting state, allowing it to join to metal parts. The bond generated must be hermetic and must guarantee the electrical resistivity of the glass.Glass is the most important part of the three latter components, being responsible to generate a hermetic seal. Its main properties have been analyzed, such as: characteristic temperatures, chemical composition, particle size and microstructure. The results obtained allowed to differentiate the two most commonly used glasses, borosilicate and sodalime, relating the difference in compositions with the sealing temperature of each glass, as well as the increase in this temperature as the heating rate increases.Once the properties of the analyzed glasses are known, the glass-metal seal has been studied according to the design of the piece and the materials used. Then the hermeticity and electrical resistance of the samples were verified and their behavior as a function of temperature and external mechanical stress were studied. The temperature cycles showed that there is no significant change in the properties of sodalime glasses, while in borosilicate glasses decreased their hermeticity after temperature cycle, when the metal body had lower thickness. On the other hand, pressure tests have shown that the height of the glass was important, breaking at the bending limit of the glass. In addition, it has been found that the critical seal is the one formed with the base. As well, thesmaller the glass diameter, the more pressure the piece resists. These results were used to perform a series of numerical simulations to obtain the rupture pressures. Some results were coincident with the simulation but others no.Once the factors that influence the piece performance were known, new metallic materials for the bases have been studied, such as aluminum or titanium, which allow the company to enter new markets. With these new materials, it was necessary to determine the sealing curve and find the right glass to achieve the required tightness and electrical resistance. Solutions were found for both metals, although with certain limitations. In the case of titanium, the required electrical resistance was not attained by the glass, while in the aluminum case, the temperature cycles requirements were not achievedFinally, the evaluation of other alternative manufacturing methods for the metal bases was carried out. Metallic samples obtained by powder metallurgy and through the MIM and MEAM processes were studied. Because the samples manufactured by powder metallurgy and MIM were commercial ones, in which it was not possible to modify their manufacturing conditions, the results have been unfavorable, while with the samples manufactured by additive metal extrusion (MEAM), a proper seal was achieved.
  

• TOVAR VARGAS, DANIELA: Processing, microstructure and mechanical properties of ceria-stabilized zirconia-based ceramics co-doped with calcia and alumina
  
  Author: TOVAR VARGAS, DANIELA
  Thesis link: http://hdl.handle.net/10803/672340
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Article-based thesis
  Reading date: 20/07/2021
  Thesis director: JIMENEZ PIQUÉ, EMILIO | ANGLADA GOMILA, MARCOS JUAN
  

  Committee:
       PRESIDENT: GALLARDO LÓPEZ, ÁNGELA MARÍA
       SECRETARI: LLANES PITARCH, LUIS MIGUEL
       VOCAL: BERMEJO MORATINOS, RAUL
  Thesis abstract: In recent years, zirconia ceramics have been used in many applications. Some of them include tool forming due to its high strength and fracture toughness, thermal barrier coatings on turbines engines due to its low thermal conductivity, as an electrolyte in the elaboration of Solid Oxide Fuel Cells (SOFC) for its high ionic conductivity, and in the manufacture of dental implants for its biocompatibility and its aesthetic appearance. Biomedical zirconia is mainly tetragonal zirconia doped with 3 mol% of yttria (3Y-TZP). However, it is sensitive to the hydrothermal degradation phenomenon. This is the reason for investigating the processing and mechanical properties of ceria doped zirconia-based ceramics since their high aging resistance is well established. Ce-TZP ceramics present low strength due to their large grain size. Many studies have been devoted to finding a way to reduce grain size.Several methods have been proposed, such as the addition of a stabilizer, or a second phase, the improvement of powder processing, or the modification of the sintering conditions. Following the above ideas, this thesis aims to reduce the grain size in 10Ce-TZP ceramics (10 mol% CeO2), with the aim to increase the strength by three different strategies. The first strategy has been manufacturing composites with alumina (a-Al2O3) addition by colloidal processing. The second strategy has been to use calcium oxide (CaO) as a co-stabilizer and adding alumina (a-Al2O3) as a second phase. The third strategy was directed to improve processing by combining ball milling, slip casting, and subsequent powder grinding. In all these studies microstructural characterization, and mechanical has been performed. The hydrothermal degradation test was also measured to evaluate the resistance of the elaborated composites to aging. The results obtained in the two first strategies showed a reduction in the grain size, which led to an increase in hardness and strength. However, in the third strategy, the grain size was not reduced as much as in the previous strategies, which allowed to obtain a moderate fracture toughness and a slight increase in hardness and strength compared to the 10Ce-TZP base material. A high hydrothermal degradation resistance was achieved for all the elaborated composites in all the strategies.
  

• VIDAL GIRONA, ELIA: Development of metallic functionalized biomaterials with low elastic modulus for orthopedic applications
  
  Author: VIDAL GIRONA, ELIA
  Thesis link: http://hdl.handle.net/10803/671888
  Programme: DOCTORAL DEGREE IN MATERIALS SCIENCE AND ENGINEERING
  Department: (CEM)
  Mode: Article-based thesis
  Reading date: 12/02/2021
  Thesis director: RODRÍGUEZ RIUS, DANIEL | RUPEREZ DE GRACIA, ELISA
  

  Committee:
       PRESIDENT: SARDA, STÉPHANIE
       SECRETARI: ESPAÑOL PONS, MONTSERRAT
       VOCAL: MONTUFAR JIMENEZ, EDGAR BENJAMIN
  Thesis abstract: Titanium (Ti) and Ti allor-; have been used for decades for bone implants and prostheses dueto its mechanical reliability and good biocompatibility. However, implant-related infections, lack ofosteointegration with the surrounding bone, and the mism atch of mechanical properties between implant and bone, remain among the leading reasons for implant failure . In the present PhD thesis, two strategies have been studied to increase implant lñability: fabrication of porous Ti structures and surface functionali zation.The stiffness mismatch between titanium implant and bone can cause significant bone resorption, which can lead to serious complications such as periprosthetic fracture during or after relñsion surgery. Titanium surface piar-; a major role in the bone­ prosthesis interactions, notonlyto promote initial cell adhesion butalso to avoid bacterial adhesion . One strategystudied in the thesis has been the developmentand manufacturing ofporous Ti structures.A scaffold with a porosity of75% has been preparad bydirect ink writing, with the objective of reducing the apparent modulus elasticityofli prostheses. In this wor1<:, porous Ti structures with a stiffness and compressive strength of2.6 GPa and 64.5 MPa respectively has been manufacturad. To this end, a new ink fonnulation was designad based on the mixture of athenn ose nsitive h rogel with Ti irregular powder particles with a mean particle size of 22.45 µm.A thennal treatrnentwas optimized to ensure the complete elimination ofthe binder before the sintering process, in orderto avoid contamination ofthe titanium structures.The understanding of infections is closely linked to the concept ofthe "race for the surface". The winner of this race (cell versus bacteria) decides if a solid anchoring between implant and bone will be achieved or if bacteria! growth will lead to a periprosthetic infection. Another strategy studied on this thesis focuses on the functionalization of the Ti surface. First. surface of Ti scaffolds were functionalized with a cell adhesion fibronectin recombinant fragment for optimizing cell adhesion. Mditionally, a multifunctional coating based on the potential of calcium phosphate coatings to be used as carriers for drug deliverywas also studied to achieve a balance between cell attachmentand reduction ofbacterial adhesion. Porous Ti structures have beén successfullycoated with a one-step pulsed electrodeposition process achielñng a unifonn calcium phosphate layer both on the inner and outer the surface ofthe scaffold, with adhesion strengths over 22 MPa. The co­ deposition of an antibacterial agentwith a pulsad and reverse pulsed electrodeposition was achieved on both smooth and open-cell Ti surfaces. The ralease rate ofthe antibacterial agentcan be modulated within hours ordar-; timeframe byadjusting the coating conditions and without altering the antimicrobial potential ofthe loaded antibacterial agent itself. The biofunctionalized coatings exhibited a noteworthy in lñtro antibacterial actilñty against S. aureus and E. coli bacteria strains, with a significant decrease of lñable attached bacteria to the treated surfaces. Cell culture tests also showed that CHX-loaded Ti structures presentad an improved cell adhesion comparad to thatofuntreated Ti.Therefore, the proposed strategies can efficiently impro-.e orthopedic implants in tenns of improlñng biointegration and microbial adhesion resistance.
  

Last update: 16/10/2021 05:11:51.

Research groups

• BBT-Biomaterials, Biomechanics and Tissue Engineering
• CDAL-Light Alloys and Surface Treatment Design Centre
• CIEFMA-Structural Integrity, Micromechanics and Materials Reliability Centre
• e-PLASCOM-Eco-friendly Plastics and Composites
• InSup-Surface Interaction in Bioengineering and Materials Science Research Group
• POLY2-Polyfunctional polymeric materials
• PROCOMAME-Conformation Processes of Metallic Materials

Teachers

• Alcala Cabrelles, Jorge
• Arencon Osuna, David
• Baile Puig, Maria Teresa
• Benito Paramo, Josep Antoni
• Cabrera Marrero, Jose Maria
• Calvo Muñoz, Jesica
• Canal Barnils, Cristina
• de Redondo Realinho, Vera Cristina
• de Sousa Pais Antunes, Marcelo
• Engel Lopez, Elisabet
• Español Pons, Montserrat
• Fargas Ribas, Gemma
• Fernandez Aguado, Enrique
• Ginebra Molins, Maria Pau
• Jimenez Pique, Emilio
• Llanes Pitarch, Luis M.
• Manero Planella, Jose M.
• Martin Fuentes, Enric
• Mas Moruno, Carlos
• Maspoch Ruldua, Maria Lluïsa
• Mateo Garcia, Antonio
• Pegueroles Neyra, Marta
• Picas Barrachina, Josep A.
• Riera Colom, Maria Dolores
• Roa Rovira, Joan Josep
• Rodriguez Rius, Daniel
• Ruperez de Gracia, Elisa
• Sanchez Soto, Miguel Angel
• Santana Perez, Orlando
• Velasco Perero, Jose Ignacio

• Casellas Padro, Daniel