POLAR ANISOTROPY OF MICROHARDNESS FOR REFRACTORY BORIDE SINGLE CRYSTALS OF DIFFERENT SYNGONY

摘要

Anisotropy of Knoop microhardness is measured in different directions within the limits 0-90 and 0 - 180 deg with a step in the azimuth of 22.5e in different identified faces of single crystals belonging to different crystal lographic syngony of refractory borides, some of which are used as antioxidants in the production of catbon-containing refractories. Single crystals are prepared from Al solution-melts with slow cooling of the sys-tem from 1200 - 1400 to 20deg C. Experimental data for polar anisotropy of microhardness with a step in azimuth indicated are obtained for the first time and their qualitative interpretation is provided.