The correction of hardness value measured on a curved surface specimen

In view of the difficulties in solving the hardness problems, the assumptions to simplify the problems have been presented based on (1) the analogy between the elastic solution in the linear elastic indentation problem and the elastic-plastic solution derived from Meyer’s law, (2) the concept of the equivalent spherical indenter for a conical (or pyramid) indenter, and (3) Euler’s formula which relate a spherical surface with a general curved surface, in this paper. By means of these assumptions, the calculating formulas of the corrective value (or coefficient) of the hardness value measured on a curved surface specimen have been given. To examine whether the formulas obtained in this paper are right or not, we compare them with the experimental results. It is shown that all the theoretical values seem to agree with experimental data.