With a microhardness arrangement which is constructed as an accessory equipment for modern material testing machines the generation of Vickers indentation is investigated by recording of the load during a programmed penetration of the pyramide. For all engineering materials investigated the relation between load L and penetration depth p could be fitted by L=a1p ± a2p2 with a high degree of statistical reliability. It is derived a new hardness number which is independent of the load also in the microhardness region. By comparison it can be shown that conventionally measured Vickers hardness numbers are identical for the ductile metals but to large for brittle materials. Furtheron it is possible to determine quantitatively the change of the hardness of the surface layer disturbed by mechanical polishing. By the same experiment it is investigated in microregions of the different materials the inelastic behaviour by stress relaxation and the elastic recovery by measurement of the L-p relation during unloading.
No takes yet. Share an insight, caveat, or question.
Fröhlich et al. (1977) studied this question.