Metallurgy expert witness Dr. R. Craig Jerner, Ph.D., PE, describes the metal failure analysis process:
The title, Metallurgical Failure Analysis, aptly describes the process, i.e., the analysis of a metal failure. In deference to my mechanical engineering friends, a metallurgist or metallurgical engineer is best equipped to analyze a metal failure. An accident or failure of a metal component, whether it is a simple consumer product such as a hammer or chisel, or a complex multi-component machine such as an airplane or a space shuttle, will normally not be a “simple” failure. Failures are normally complex. Often two, three or more separate but necessary circumstances or events are required to cause the failure or accident. Solving such a complex problem is much like solving a multi-piece jigsaw puzzle.
Guessing about a jigsaw puzzle picture from one or two puzzle pieces will usually lead you to a wrong conclusion. Guessing prematurely from one or two “facts” about the cause of a failure or accident will also usually lead to a wrong conclusion. A series of accident events and evidence will usually fit exactly with another set of events and evidence thereby allowing more of the true picture to be revealed.
A metallurgist’s analysis of a metal failure may include many of the following: accident scene/site examination and documentation (including photo documentation), evidence preservation, library/standards/literature review, laboratory examination and testing, exemplar testing, engineering calculations, data and file analysis and synthesis, report preparation and expert witness testimony.
For more, see http://www.metallurgist.com/index.html