The field of electron probe microanalysis has rapidly spread from metallurgy, geology, and biology to many allied fields. It is the purpose of this discussion to cover an application that has not received much attention—namely, the study of relay contact surfaces with this technique.

In this case, many of the problems encountered are somewhat different, but the ultimate results are quite gratifying. Sample preparation is greatly simplified inasmuch as the surface condition is of prime interest and absolutely no preparation is a prerequisite. Unfortunately, this does lead to some problems of sample mounting and makes the interpretation of results more difficult. Examples are given of the types of information that can be obtained on the substrate materials as well as the finished plated contacts.