Full-time study

4 years

prof. Ing. Ivo Dlouhý, CSc.

Chairman :
prof. Ing. Ivo Dlouhý, CSc.
Councillor internal :
prof. RNDr. Karel Maca, Dr.
prof. RNDr. Pavel Šandera, CSc.
Councillor external :
prof. RNDr. Antonín Dlouhý, CSc.
prof. Mgr. Tomáš Kruml, CSc.

The aim of the doctoral study is:
• To ensure the education of graduate creative workers in the field of physics of materials and materials sciences for their work in the academic sphere, institutes of basic and applied research and departments of research and development of industrial companies.
• To enable the doctoral student to develop talent for creative activities and further development of a scientific or engineering personality. To ensure the development of their ability to process scientific knowledge in the field of study and related fields, both literary and their own acquired theoretical or experimental work.
• To develop the habits necessary for creative activity in the field of materials sciences and related fields and for communication with the scientific community.
• The doctoral study is primarily focused on basic research into the relationship between the structure, behaviour and properties of materials in relation to the parameters of their preparation with a focus on materials based on metals, polymers, and ceramics and their composites.
• The purpose of research carried out by doctoral students is also the development of new materials, optimization of useful properties of materials and prediction of their service life on the basis of theoretical and computational methods based on experiments.

the graduate's profile, based on the current state of scientific knowledge and creative activities in the field of materials physics and materials science.
• The graduate of the study is a mature personality, creatively thinking, able to formulate and implement research projects of theoretical and experimental nature, or to develop and apply the knowledge of these projects in production practice.
• The doctoral student will gain broad theoretical and experimental knowledge in the field of modern materials and methods of their development, preparation, study of their behaviour under mechanical, thermal or corrosion stress and properties in relation to the structure.
• The graduate will be an expert capable of exact descriptions of processing processes, designs of very complex products from metals, ceramics and polymers and composites with these matrices, tools for their production, mathematical simulations of processing processes, modelling of mechanical behaviour of materials or predictions of its properties and durability.
• Graduates will be equipped with a broad knowledge of the properties and behaviour of structural ceramics, polymers, metallic materials and composites and processes in processing into final products and tools, both on a theoretical and practical level.
• Graduates are expected to be employed in leading positions associated with technical and technological preparation of production, where they will be able to develop production processes and their design on the basis of knowledge acquired through studies.
• Graduates will also be employed as research and development staff in applied research centres, and after subsequent scientific-pedagogical and foreign practice also as academic staff of universities and academic institutions.

• The doctoral programme "Materials Science" is built so that the graduate is a self-acting material specialist applicable in a number of areas, able to formulate and implement research, development and application projects.
• With regard to the role of materials in all design applications and technologies, creative workers in the field of materials science and engineering will always find appropriate applications at home and abroad, including in the following areas.
- Within the framework of postdoctoral projects at a number of foreign workplaces for graduates with the ambition to be active in the fields of scientific research.
- In the form of direct involvement in research teams of academic and applied research workplaces.
- In the departments of research and development of industrial enterprises, or interdisciplinary teams of these workplaces.
• In all these cases, full-fledged involvement can be expected not only in the Czech Republic, but also at foreign workplaces.

See applicable regulations, DEAN’S GUIDELINE Rules for the organization of studies at FME (supplement to BUT Study and Examination Rules)

The rules and conditions of study programmes are determined by:
BUT STUDY AND EXAMINATION RULES
BUT STUDY PROGRAMME STANDARDS,
STUDY AND EXAMINATION RULES of Brno University of Technology (USING "ECTS"),
DEAN’S GUIDELINE Rules for the organization of studies at FME (supplement to BUT Study and Examination Rules)
DEAN´S GUIDELINE Rules of Procedure of Doctoral Board of FME Study Programmes
Students in doctoral programmes do not follow the credit system. The grades “Passed” and “Failed” are used to grade examinations, doctoral state examination is graded “Passed” or “Failed”.

Brno University of Technology acknowledges the need for equal access to higher education. There is no direct or indirect discrimination during the admission procedure or the study period. Students with specific educational needs (learning disabilities, physical and sensory handicap, chronic somatic diseases, autism spectrum disorders, impaired communication abilities, mental illness) can find help and counselling at Lifelong Learning Institute of Brno University of Technology. This issue is dealt with in detail in Rector's Guideline No. 11/2017 "Applicants and Students with Specific Needs at BUT". Furthermore, in Rector's Guideline No 71/2017 "Accommodation and Social Scholarship“ students can find information on a system of social scholarships.

The doctoral study programme follows on the bachelor's and master's education in the specialization of Materials Engineering (B-MTI) and the master's program Materials Engineering (M-MTI). During the course, students are provided with a balanced basis of theoretical and engineering disciplines supplemented by laboratory teaching with the maximum possible use of the latest instrumentation and computer technology.
For other adepts with education at other universities, the completed master's degree must be permeable to the fields of Materials Science and Engineering, Materials Physics, Solid State Physics, Materials Chemistry, etc.
The doctoral programme in "Materials Science" replaces the existing doctoral study programme in "Physical and Materials Engineering". Both programmes are conceptually identical and after granting a favourable opinion with the accreditation of the "Materials Science" programme, doctoral students will complete their studies within the currently accredited programme.

1. Development of hybrid composites compensating shrinkage at pyrolysis

   The main goal of the doctoral thesis will be the design and characterization of hybrid composites using, for example, fillers to suppress and/or control matrix shrinkage during partial pyrolysis. The work will consist of analyses of microstructural changes of hybrid materials based on polysiloxane resins, optimization of the preparation of composites and their characterization. Furthermore, from the determination of the influence of the method of compensation of shrinkage during pyrolysis on the resulting properties of the matrix. The use of matrix precursors thus prepared for the preparation of fibre-reinforced composites will also be studied. The influence of shrinkage compensation on the micromechanisms of failure and other properties of the prepared hybrid composite materials will be also studied. Due to the complicated microstructure and the number of present interfaces, it will be necessary to develop a procedure to obtain local properties describing the interfaces for numerical simulations. Simulations will result in the prediction of stress distribution formed during the material preparation. Within the work, it will be necessary to elaborate the issues related to the influence of the surrounding matrix by the presence of e.g. fillers, i.e. local changes in the microstructure, stress state and the like, and the impact of these changes on global characteristics. The involvement of advanced techniques of electron microscopy, atomic force microscopy, acoustic emission, nanoindentation, etc. will be necessary to achieve the set goals.

   Tutor: Chlup Zdeněk, Ing., Ph.D.

2. Fatigue properties of steels with tailored crystallography processed by selective laser melting

   Additive manufacturing offers an effective option of design and rapid prototyping for diverse industry branches. It is expected that these techniques will find applications in small- to medium-scale production in the case of critical components with high production and service demands. Generally, additive manufacturing opens novel and revolutionary production opportunities in terms of shape complexity, previously impossible to achieve by conventional manufacturing processing. One of the most frequently used techniques of additive manufacturing is selective laser melting which utilizes powder feedstock, which is locally melted by the controlled movement of a laser beam. The melting and subsequent solidification results in the fabrication of a structure with the desired shape. Recently, several studies explored the possibility to control the solidification process by laser scanning parameters optimization with the aim to control the crystallographic orientation of microstructure. This approach opens the novel and interesting options for the industry – the fabrication of complex components with tailored microstructure with respect to expected service loading. The topic of PhD thesis will be focused on optimization of selective laser melting parameters to obtain materials with certain microstructure and subsequent characterization of the effect of various crystallographic orientation on fatigue behaviour and fatigue performance. The student will cooperate tightly on SLM processing parameters optimization with the research staff of the NETME centre. Furthermore, the student will adopt deep user knowledge of scanning electron microscopy (SEM) which will be intensively used for the characterization of fabricated microstructures. Fatigue tests will be carried out by modern Instron and MTS testing machines. Obtained results will be analysed with relation to the findings of thorough characterization of deformation mechanisms detected by optic and electron microscopy. The results will contribute to a deeper understanding of fatigue resistance of SLM-processed steels.

   Tutor: Šmíd Miroslav, Ing., Ph.D.

3. Chemical inhomogeneity in wrought Cr–Ni austenitic stainless steels: The origin and its impact on microstructural stability

   Within a stainless steel family comprising five basic types the wrought Cr–Ni austenitic stainless steels (ASSs) (AISI 300 grade) still occupy a privileged position due to their exceptional corrosion resistance and prominent mechanical and technological properties. The f.c.c. paramagnetic austenitic structure of most of these alloys is known to be, however, metastable, i.e. it can partially transform to ferromagnetic b.c.c. '-martensite during cooling and/or plastic straining. In the absolute majority of studies dealing with the stability of wrought AISI 300 grade austenitic stainless steels so far these materials are considered to be chemically homogeneous after numerous steps of hot- and cold-working. The importance of local chemistry in the form of chemical banding within various semi-product forms (long vs. flat) on the destabilization of austenite during cyclic straining of wrought Cr–Ni ASSs and as well as its non-negligible role on the hydrogen environment embrittlement (HEE) has been recognized only recently. The proposed comprehensive study will include the following three principal goals. (i) Experimental study of the origin of chemical banding during the whole industrial production way of Cr–Ni ASSs starting from continuously casted slabs and followed hot rolled semi-products up to the final cold-worked sheets. (ii) Systematic monitoring of chemical homogeneity of AISI 300 series austenitic stainless steels (AISI 304, 316, 321 and some others) in various industrially produced wrought forms (cylindrical bars, thick and thin plates) and its impact on the '-martensite formation during monotonic and cyclic straining under different external and internal conditions in the perspective of their physical metallurgy. (iii) The clarification of the role of '-martensite formation on the HEE and fracture behavior of ASSs using tensile tests under internal and external hydrogen conditions with emphasis on the semi-product form and local chemistry. The chemical heterogeneity across the whole cross-section of various semi-product forms will be characterized by color metallography and quantitatively by EDS technique. The volume fraction of DIM will be evaluated by X-ray diffraction and Ferritescope. Modern high resolution microscopic techniques (SEM–FEG, ECCI, EBSD and TEM) as well as color metallography will be adopted to reveal the formation, distribution and morphology of DIM at different scales.

   Tutor: Man Jiří, Ing., Ph.D.

4. Influence of defects on fatigue life of nickel superalloys

   The topic of the work will be to characterize the influence of casting defects and geometrical notches representing stress concentrators on the fatigue life of nickel superalloy components. In particular, the relationship between the microstructure of the superalloy and its tolerance to defects during cyclic loading at elevated temperatures will be monitored. Fatigue tests will be performed on specimens without and with geometrical notches. Based on the analysis of tested specimens using scanning and transmission electron microscopy, the influence of defects on the initiation of fatigue cracks and their further propagation will be quantified. The results of the work will expand knowledge about the influence of defects on the fatigue life of nickel superalloy components and help to predict their fatigue life.

   Tutor: Fintová Stanislava, doc. Ing., Ph.D.

5. Influence of loading frequency on the mechanism of fatigue damage

   The dissertation thesis will focus on the identification of mechanisms of fatigue damage of metallic materials depending on the loading rate. It will focus mainly on fatigue tests at different loading frequencies, with emphasis on high-frequency tests and their interpretation. Using scanning and transmission electron microscopy, the mechanisms of fatigue damage of metallic materials at different frequencies (rate) of loading will be studied and from the results, it will be possible to deduce the relationship between traditional and high-frequency fatigue tests. The results of the work will help to gain a deeper understanding of the effect of loading rate on the mechanism of fatigue damage of metallic materials and contribute to the prediction of fatigue life based on high-frequency tests.

   Tutor: Fintová Stanislava, doc. Ing., Ph.D.

6. Low-cycle fatigue of austenitic stainless steel AISI 316L manufactured by selective laser melting (SLM)

   Cyclic plasticity and low cycle fatigue behavior of 316L austenitic stainless steel produced by the most frequently used additive manufacturing technology – selective laser melting (SLM) will be comprehensively studied. Cylindrical near net-shape testing specimens fabricated under various SLM processing parameters (virgin/reused powder, nitrogen/argon protective atmosphere) and post-processing heat treatments (stress-relief, solution annealing) will be fatigued under total strain amplitude control at room temperature. A particular attention will be paid to the improvement of surface integrity by electropolishing and its impact on fatigue life. Microstructural changes and fatigue damage mechanisms (initiation and growth of short fatigue cracks) in SLM 316L steel with a unique but non-equilibrium hierarchical solidification structure will be in detail characterized by high-resolution microscopic techniques (SEM–FEG, TEM, AFM, FIB, EBSD). Experimental data obtained will be compared with relevant characteristics of conventionally produced wrought counterparts.

   Tutor: Man Jiří, Ing., Ph.D.

7. Microscopic processes at the fatigue crack tip

   Fatigue crack propagation is a process that is described macroscopically using quantities such as the amplitude of the stress intensity factor, the J-integral or the plastic part of the J-integral. There are many models of crack propagation at the microscopic level that consider plastic deformation around the crack tip, but which differ in detail. Advances in experimental methods allow a more accurate and detailed experimental study of these processes and subsequently their more accurate description and modeling using advanced methods of molecular statics and dynamics. The aim of the work will be to gather as much details as possible about the processes at the crack tip during its growth by modern methods: high-resolution digital image correlation (HR DIC), electron channeling contrast imaging (ECCI), high-resolution electron backscatter diffraction (HR EBSD) and observation of lamellae prepared using the focused ion beam technique in a transmission electron microscope. Observations will be supplemented by simulation of microscopic processes using molecular dynamics or discrete dislocation dynamics. The measurement methods will first be validated on 316L steel and then applied to materials reinforced with oxide dispersion (ODS) and prepared using additive manufacturing.

   Tutor: Kuběna Ivo, Ing., Ph.D.

8. Microscopic processes at the fatigue crack tip

   Fatigue crack propagation is a process that is described macroscopically using quantities such as the amplitude of the stress intensity factor, the J-integral or the plastic part of the J-integral. There are many models of crack propagation at the microscopic level that consider plastic deformation around the crack tip, but which differ in detail. Advances in experimental methods allow a more accurate and detailed experimental study of these processes and subsequently their more accurate description and modeling using advanced methods of molecular statics and dynamics. The aim of the work will be to gather as much details as possible about the processes at the crack tip during its growth by modern methods: high-resolution digital image correlation (HR DIC), electron channeling contrast imaging (ECCI), high-resolution electron backscatter diffraction (HR EBSD) and observation of lamellae prepared using the focused ion beam technique in a transmission electron microscope. Observations will be supplemented by simulation of microscopic processes using molecular dynamics or discrete dislocation dynamics. The measurement methods will first be validated on 316L steel and then applied to materials reinforced with oxide dispersion (ODS) and prepared using additive manufacturing.

   Tutor: Pantělejev Libor, doc. Ing., Ph.D.

9. Theoretical study of magnetic states in Heusler alloys

   Quantum-mechanical methods have recently become a standard tool for studying numerous materials properties. These so-called ab initio methods offer a high reliability, accurancy and universal applicability to a wide range of systems. The ab initio methods also excellently complement experimental characterization techniques because quantum-mechanical calculations describe the matter at length scales beyond the reach of even the best electron-microstopy techniques. When studying magnetic systems, the ab initio methods represent a unique set of methods because magnetism is essentiually a quantum-mechanical effect inherently related to the electronic structure. The aim of this work is to apply the quantum-mechanical methods when studying different magnetic states in Heusler-structure alloys with different level of ordering, both chemical and magnetic, and including additional defects. The calculations will focus on very prospective magnetic shape memory alloys that are currently very intensively studied. A projector augmeted wave method will be used as implemented in the VASP package.

   Tutor: Friák Martin, Mgr., Ph.D.