Course detail

Fractography and Micromechanisms of Failures

FSI-9FMPAcad. year: 2020/2021

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.

Learning outcomes of the course unit

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.

Prerequisites

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

Co-requisites

Not applicable.

Recommended optional programme components

Not applicable.

Recommended or required reading

Fractography, ASM Handbook, Vol. 12, ASM International, 1987, 517 s., ISBN: 978-0-87170-018-6 (EN)
SURESH, S. Fatigue of Materials. 2nd edition. Cambridge, UK: Cambridge University Press, 1998. ISBN 0-521-57847-7. (EN)
Fatigue and Fracture, ASM Handbook, Vol. 19, ASM International, 1996, 1057 s., ISBN: 0-87170-385-9 (EN)
DOWLING, Norman E. Mechanical Behavior of Materials: Engineering Methods for Deformation, Fracture, and Fatigue. Engelwood Cliffs, N.J.: Prentice-Hall, 1993. ISBN 0-13-026956-5. (EN)
Failure Analysis and Prevention, ASM Handbook, Vol. 11, ASM International, 2002, 1050 s., ISBN: 0-87170-704-7 (EN)
SURESH, S. Fatigue of Materials. 2nd edition. Cambridge, UK: Cambridge University Press, 1998. ISBN 0-521-57847-7. (EN)

Planned learning activities and teaching methods

The course consists of lectures explaining the basic principles and theory of the discipline.

Assesment methods and criteria linked to learning outcomes

The final evaluation will be based on a presentation of students focussed on a given topic - assessment of failure in service.

Language of instruction

Czech

Work placements

Not applicable.

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.

Specification of controlled education, way of implementation and compensation for absences

Attendance at lectures is not mandatory, nevertheless, it is highly recommended.

Classification of course in study plans

  • Programme D-MAT-P Doctoral, 1. year of study, winter semester, 0 credits, recommended

Type of course unit

 

Lecture

20 hours, optionally

Teacher / Lecturer

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.