Course detail

Fractography and Micromechanisms of Failures

FSI-9FMP Acad. year: 2024/2025 Winter semester

In the frame of the course “Fractography and fracture micromechanisms”, causes and consequences of different types of failures will be explained to students. Fractography and fracture surface morphology as manifestation of the material response to mechanical loading. Fractographic methods and procedures applied during fracture damage, including fractographic terms systemization. Nature and ways of fracture identification based on crack trajectory (transcrystalline, intercrystalline) and fracture micromechanisms (cleavage, ductile fracture, quasi-cleavage, fatigue, and creep fracture as well as special fracture types). Lectures will be focused not only on fractures originated under laboratory conditions, but also on damages occurred during service of components and with identification of these fractures, including expert witness analyses.

Language of instruction

Czech

Entry knowledge

Good knowledge of strength properties of materials and testing of mechanical properties is assumed.

Rules for evaluation and completion of the course

The final evaluation will be based on a presentation of students focussed on a given topic – assessment of failure in service.
Attendance at lectures is not mandatory, nevertheless, it is highly recommended.

Aims

The course focuses on the explanation of the causes of machine-part failures, failure micromechanisms, methods of macrofractographic and microfractographic studies, classification and description of fracture appearance with the aim of making students familiar with the potentials of applying fractography to the solution of practical production problems, damages assessment and determination of their causes, materials selection optimisation, etc.
The knowledge of failure micromechanisms and methods of studying them. Understanding the relations between the properties of materials, the causes of their failures, and ways of preventing failures. The application of fractography as an important tool in solving production problems and breakdowns.

The study programmes with the given course

Programme D-MAT-K: Materials Sciences, Doctoral, recommended course

Programme D-MAT-P: Materials Sciences, Doctoral, recommended course

Type of course unit

 

Lecture

20 hours, optionally

Syllabus

1. Fracture causes and consequences. Fracture surface as a complex manifestation of materials structure response to mechanical loading.
2. Procedures and experimental methods exploited during fractographic analyses.
3. Definition and systemization of fractographic concepts and failure micromechanisms characterization.
4. Transcrystalline and intercrystalline failures. Cleavage and ductile micromechanism of failure.
5. Cleavage intercrystalline and transcrystalline fracture as manifestation of materials degradations.
6. Fatigue fractures.
7. Creep fractures.
8. Stress corrosion cracking, hydrogen embrittlement.
9. Special cases of fractures.
10. Methodology for solving the causes of fractures during operations, expert witness analyses.