Selecting Equipment for Failure Analysis

For every failure, whether at the field test site or with the customer, there is a related cause. It is imperative that the exact cause be determined in order that appropriate corrective action may be taken. The field test engineer is immediately faced with deciding where the analysis shall be performed. The choices range from analysis at the field test site to sending the parts to the materials laboratory. The key in handling the analysis lies in knowing what equipment is available and the capabilities of each.

This paper offers guidelines to aid in the decision whether a failure should be analyzed immediately in the field or returned to the laboratory. Furthermore, the capabilities of individual pieces of equipment are described while simultaneously out-lining methods which were developed to assist the failure analyst in selecting which tools would be most appropriate for a given analysis. The majority of the tests available, including hardness, fatigue properties, optical and electron microscopy and x-ray and electron spectrometers, are discussed with particular attention given to those tools most often used during failure analysis in the ground vehicle industry. Examples are included to illustrate the types of information found and how that information relates to the cause of failure. For those cases where broken parts are returned to the laboratory, suggestions are offered in how to protect the parts so that the failure analyst will still be able to uncover the cause of failure.