On Methods of Measurement of Microhardness on Anisotropic Crystals

摘要

The study of hardness on anisotropic crystals with the help of appropriate specially shaped indenters will make it possible to refer the measured value to definite crystallographic planes. It is most expedient to relate measurements of hardness with the glide planes (or cleavage planes), since these planes play the main role in development of deformation of a crystalline anisotropic body. It is natural to characterize microhardness by average contact pressure or average specific work of deformation; therefore, there should be observed the requirement of maximum conformity between the shapes of the indenter and of the indentation. Measurement of microhardness on basal crystallographic planes with the help of special indenters makes it possible to attain the most complete conformity. Special indenters also make it possible to considerably decrease errors of measurements which are due to distortion of the shape of the indentations, the appearance of cracks, and so forth. Furthermore, reproducibility of results will be increased, since for crystals of many crystallographic systems there will be required indenters in the shape of a regular trihedral pyramid, the accuracy of manufacture of which is very high. (Author)