IntermediateTopic 59 of 100Materials & Chemical
Failure analysis
Fractography and testing find root causes of failures.
In depth
Systematic investigation of failures: collect history, visual and fractographic examination (SEM), chemical analysis, metallography, mechanical tests, stress analysis and root cause determination. Typical causes: overload, fatigue, corrosion, creep, wear, manufacturing or design flaws.
Key points
- Beach marks vs dimples
- Chain of events
- Recommendations and prevention
ExampleA shaft failing with beach marks and a final fast fracture zone indicates fatigue.
What is Failure analysis?
Fractography and testing find root causes of failures.
Why is it important to understand failure analysis?
Failure analysis finds why parts break, which prevents repeats and supports legal and safety investigations.
What is fractography?
The study of fracture surfaces, which reveals whether failure was ductile, brittle, fatigue or corrosion related.
What is a root cause?
The underlying reason for a failure, not just the immediate event, so that corrective action prevents recurrence.
How is Failure analysis used in practice?
Typical applications include investigating a fatigue crack in a pressure line, identifying a corrosion failure in a heat exchanger tube and studying the fracture surface of a broken shaft to find the cause.
What should I learn before Failure analysis?
Study "Materials selection" first (topic 58 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
What are the key points of Failure analysis?
Beach marks vs dimples. Chain of events. Recommendations and prevention.
Can you give an example of Failure analysis?
A shaft failing with beach marks and a final fast fracture zone indicates fatigue.
What comes after Failure analysis?
The next topic is "Non-destructive testing", which builds directly on this one.
How difficult is Failure analysis?
It is classed as Intermediate in Materials & Chemical (topic 59 of 100). It is an intermediate topic. Work through the beginner topics in Materials & Chemical first.