Some ASM International Failure Analysis Society members are preparing to revise the ASM Metals Handbook on Failure Analysis. I was on the committee the last time and sincerely thought it would stand for the rest of my life. It was a monumental effort, and now we’re breaking it into two volumes to be able to include the material we left out the last time. It’s going to be a monumental effort this time, too.
My main contribution has to do with how to do a failure analysis. It’s not just the physical tests that are performed, but the mental aspects of the work. As I contemplated this subject, I had an epiphany. Failure analysis can be “boiled down” to two things.
Firstly, clear your mind so that you can distinguish facts from opinions. This is much harder than it seems. The entire Eastern science of yoga is focused on this topic. Unless we really work to be able to see reality, we are doomed to see only a dim reflection through layers of unseen filters.
Modern neuroscience is also hard at work revealing many of these filters. But the most famous practitioners of yoga have at least a 1,500-year head start. Hence, the first word of the headline, Om. Clear your mind. Learn to think with both rational and creative means. Learn to tell the difference between actual perceptions that come into the sensory receptors and the conclusions that we draw as they work their way through the subconscious mind until we finally become aware of “that broken wrench.”
Secondly, learn to preserve evidence. Evidence preservation is not a step on the list of things to do during a failure analysis. Evidence preservation is the process that applies to every step of the investigation.
Background data collection is part of evidence preservation, and evidence preservation is part of background data collection. If you don’t get an adequate understanding of the situation, you might not even realize what the point of the investigation is. It’s important to get specific questions to guide the work.
Evidence preservation is part of deciding where and how you will cut any samples from the subject parts. Evidence preservation is documenting the actual positions of the cuts you make. Evidence preservation is refraining from cleaning the part until you are sure that you know what the dirt is; deciding how to clean the part and whether you need to save what you cleaned off; and cleaning the part after deciding how to accomplish that without dissolving the features you want to see.
The spectrum of approaches to failure analysis is wide. There is room for practitioners from many different areas of expertise. But no matter what, evidence preservation will be a skill to cultivate during every failure-analysis project.
People who sell real estate like to remind their clients that there are three things that determine the value of a property: location, location, location. I have realized that one way to think about failure analysis is that it is all about evidence preservation, evidence preservation, evidence preservation. If you are not thinking this way, you are not doing failure analysis. You are just “putzing” around in the lab.
You may get lucky much of the time. If you are knowledgeable about the products you analyze, you may get lucky most of the time. But without a formal method to preserve evidence, you are unlikely to get lucky all of the time. As they say, luck favors those who are prepared to welcome her.