Evaluation of microhardness correction procedures

Abstract

The major objective of the present investigation is to develop empirical procedures for correcting microhardness values for the size effect. Such correction procedures can be expected to be useful in the determination of equivalent bulk hardness values in the highly strained regions just beneath worn or eroded surfaces. In this paper two empirical correction procedures were defined and their usefulness was evaluated on three single-phase materials, namely iron, Cu-2Si alloy and 7075 aluminium. It is found that the hardness subtraction method (one of the two correction procedures) predicts most accurately the equivalent bulk hardness values. Finally, the methodology for converting the corrected microhardness-depth profile beneath a Brinell indentation to an equivalent strain-depth profile is illustrated and the validity of such a procedure is demonstrated.