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Questions and Answers
What is the course code for Failure Analysis?
What is the course code for Failure Analysis?
IM417
Who is the lecturer for Failure Analysis?
Who is the lecturer for Failure Analysis?
Dr. Mohamed Khamis
What is the credit hours for Failure Analysis?
What is the credit hours for Failure Analysis?
3
What are the prerequisites for Failure Analysis?
What are the prerequisites for Failure Analysis?
Where are the tutorials and lab for Failure Analysis held?
Where are the tutorials and lab for Failure Analysis held?
What is the percentage weighting of the final exam in the Failure Analysis course?
What is the percentage weighting of the final exam in the Failure Analysis course?
Which of the following is NOT a technique for failure analysis covered in the course?
Which of the following is NOT a technique for failure analysis covered in the course?
The course text book is "Why Metals Fail" by Barer,R.D. and Peters, B.F.
The course text book is "Why Metals Fail" by Barer,R.D. and Peters, B.F.
Which of the following are the main engineering metals discussed in the course?
Which of the following are the main engineering metals discussed in the course?
What is the primary material discussed in the course when talking about ‘interesting failures’?
What is the primary material discussed in the course when talking about ‘interesting failures’?
The course's objective is to investigate the material facts surrounding a failure.
The course's objective is to investigate the material facts surrounding a failure.
Which of the following is NOT a factor contributing to failure?
Which of the following is NOT a factor contributing to failure?
What is the organization that provides the process that is followed in Failure Analysis?
What is the organization that provides the process that is followed in Failure Analysis?
Which of the following is a technological tool NOT used in Failure Analysis?
Which of the following is a technological tool NOT used in Failure Analysis?
Optical Microscopy has a larger depth of field than Scanning Electron Microscopy.
Optical Microscopy has a larger depth of field than Scanning Electron Microscopy.
What is the name of the chemical analysis technique often used in SEM that uses the energy dispersive X-ray?
What is the name of the chemical analysis technique often used in SEM that uses the energy dispersive X-ray?
Spark Emission Spectroscopy causes elements to emit light with wavelengths that are dependent on the concentration of the element.
Spark Emission Spectroscopy causes elements to emit light with wavelengths that are dependent on the concentration of the element.
Optical Microscopy requires the use of polished and etched specimens.
Optical Microscopy requires the use of polished and etched specimens.
SEM images show individual grains and the depth of field is small.
SEM images show individual grains and the depth of field is small.
What is the most common reason pure metals are rarely used?
What is the most common reason pure metals are rarely used?
What are two examples of alloy types discussed in the lecture?
What are two examples of alloy types discussed in the lecture?
The mechanical properties of an alloy are dictated solely by the overall composition of the alloy.
The mechanical properties of an alloy are dictated solely by the overall composition of the alloy.
Flashcards
Failure Analysis
Failure Analysis
Investigating the reasons why a part or system no longer performs as intended.
Failure Modes
Failure Modes
Different ways a component can fail, such as fracture, wear, or corrosion.
Failure Mechanisms
Failure Mechanisms
The processes that lead to failure, like fatigue, stress corrosion cracking, or creep.
Residual Stresses
Residual Stresses
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Brittle Fracture
Brittle Fracture
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Ductile Fracture
Ductile Fracture
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Fatigue Fracture
Fatigue Fracture
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Wear
Wear
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Corrosion
Corrosion
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Optical Microscopy
Optical Microscopy
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SEM(Scanning Electron Microscopy)
SEM(Scanning Electron Microscopy)
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EDS (Energy Dispersive X-ray Spectroscopy)
EDS (Energy Dispersive X-ray Spectroscopy)
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Study Notes
Course Information
- Course Title: Failure Analysis
- Course Code: IM417
- Lecture Hours: 2
- Tutorials: 2
- Credit: 3
- Prerequisites: IM315
- Lecturer: Dr. Mohamed Khamis
- Assistant: Eng. Nouran
- Delivery Method: Lectures and Tutorials Offline, Room 107
Grading
- Week 7: 30% (20% exam + 10% assignments, quizzes, and attendance)
- Week 12: 20% (10% exam + 10% assignments, quizzes, and attendance)
- Continuous Assessment: 10% (9th week project and 13th week case study)
- Final Exam: 40%
Course Description
- Techniques for failure analysis
- Modes of mechanical failure
- Residual stresses
- Brittle and ductile fracture
- Fatigue fracture
- Wear
- Corrosion
- Elevated-temperature failures
- Non-destructive testing
- Case histories
Textbooks and References
- Textbook: Wulpi, D.J. - Understanding How Components Fail - American Society for Metals, Metals Park, Ohio, 1985.
- References:
- Hutching, F.R. and Unterweiser, P.M. - Failure Analysis: The British Engine Technical Reports - American society for Metals, Metals Park, Ohio, 1981.
- Barer, R.D. and Peters, B.F. - Why Metals Fail - Gordon & Breach, Science Pub., 1970.
- ASM - Metals Hand Book, Volumes 9, 10, American Society for Metals, Metals Park, Ohio, 1983.
Course Outline
- Week 1: Introduction
- Week 2: Mechanical Behavior of Materials I
- Week 3: Mechanical Behavior of Materials II
- Week 4: Techniques of Failure Analysis
- Week 5: Residual stresses
- Week 6: Material Defects I
- Week 7: Exam
- Week 8: Material Defects II
- Week 9: Elevated Temp Failures (CREEP)
- Week 10: Ductile and Brittle Fracture
- Week 11: Fatigue Failures
- Week 12: 12th week Exam
- Week 13: Wear
- Week 14: Corrosion Failures
- Week 15: NDT
- Week No. 16: Final Exam
Failure Analysis
- Failure is a significant issue.
- Many failure modes and mechanisms.
- Overlapping failures often occur.
- Disagreements in failure analysis exist.
- Exceptions to general failure patterns are common.
- The course will focus on common failures and the failure analysis process.
- Examples of interesting failures, particularly in steel, although applicable to many materials.
What is Failure?
- A part or system no longer meets its design intent.
- Failure is not always structural.
- Examples include leaking hydraulic seals, inappropriate component stiffness, and operating/maintenance costs.
- Failure may involve any design parameter or aspect.
Objective of Failure Analysis
- Investigate material facts related to a part or system failure.
- Determine:
- Timeline of events and chain of events.
- Root-cause of incident and contributing factors.
- Fitness for purpose post-incident.
- Repair options
- Mitigating future failures.
Contributing Factor Areas
- Original Design
- Material Properties
- Manufacturing and processing
- Service Factors (Loading, Environment)
- Repair Procedures (Weld Repair)
Failure Analysis Process
-
- Problem definition
-
- Background data collection
-
- Hypothesis formulation
-
- Developing test methodologies
-
- Implementing tests and collecting data
-
- Review results, revise hypothesis
-
- End with budget, new design, or recommendations.
- ASM process to follow (https://www.asminternational.org/home)
Technological Tools
- Photography and Lighting
- Optical Microscopy (up to 600x)
- Scanning Electron Microscopy (SEM) (over 10,000x)
- Chemical Analysis (SEM/EDS, Spark Emission Spectroscopy)
Optical Microscopy
- Use polished and etched specimens.
- Limited depth of field.
- Shows individual grain structure.
SEM Image
- Shows individual grains.
- Large depth of field.
- Vacuum chamber.
Energy Dispersive X-ray (EDS)
- Elements produce distinct X-ray peaks (often primary and secondary)
Alloys
- Most metals are used in alloy form.
- Adding other elements creates a range of properties modifiable via composition and heat treatment.
- Examples: Steels and aluminum alloys
SEM Image of Alloys
- Constituents (overall composition, number/composition/weight fraction of phases, shape and size of phases).
- Mechanical properties depend on phases and manufacturing techniques (casting, heat treatments)
Processing Methods
- Metals: Casting, powder processing, cold/hot working, surface treatment, heat treatment, joining methods.
- Polymers: Injection molding, extrusion, blow molding, fibers, foaming.
Engineering Material Families
- A classification of various material groups (metals, ceramics, glasses, plastics, composites, hybrids).
Main Engineering Metals
- Steels (Low-carbon, High-carbon, Stainless, Tool).
- Cast irons (Grey, White).
Selection of Materials
- Material selection considers multiple properties.
- Example: Jet engine turbine blade
- Stiffness, high-temperature strength, thermal expansion, thermal conductivity, oxidation resistance, impact resistance, fatigue resistance, cost.
Material Properties
- Physical properties (density, melting point, resistivity, dielectric constants)
- Mechanical properties (elastic modulus, yield strength, fracture toughness)
- Thermal properties (thermal conductivity, expansion, specific heat)
- Electrical/Magnetic properties
- Environmental interactions (corrosion, wear)
- Economic factors (price, availability, production)
- Aesthetic factors (colour, texture)
Stress
- Stress equals force per unit area.
- Types of stress:
- Normal stress (simple tension/compression)
- Shear stress (direct shear, torsion)
Strain
- Normal strain: elongation per unit length.
- Shear strain: change in angle between side faces (before deformation)
Elasticity
- Interatomic bonds act like springs, linking neighboring atoms.
- Stretching/rotation of bonds leads to elastic deformation.
Measurement of Elastic Modulus
- Elastic modulus measured experimentally in engineering practice.
- Methods include tension/compression tests, beam vibration tests (natural frequency), and acoustic tests (acoustic wave velocity).
Nonlinear Elasticity
- "Elastic" implies no permanent deformation on unloading.
- Stress-strain relation can be linear or nonlinear (example: rubber).
- Tangential modulus = do / de
Beyond Elasticity
- All solid materials have an elastic limit.
- Beyond the elastic limit, brittle materials fracture, and ductile materials deform plastically.
Young's Moduli of Some Materials
- Values for various materials (e.g., diamond, tungsten, alumina, steel, copper, aluminum, concrete, nylon, rubber). Values are given in GPa.
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