Effect of Thermochemical Treatment on the Structure and Mechanical Properties of Materials Based on Aluminum Oxide

摘要

According to the standard process, normal electrocorundum is heat treated at 700°C in a rotating drum followed by air cooling. Such heat treatment increases the strength characteristics of abrasive grain. When abrasive paper made from grains with reduced brittleness is working, the effect of reducing the cutting ability due to damage and failure of the cutting surfaces is observed. An increase in the performance characteristics of the abrasive paper was studied by improving the self-sharpening of the grain. Improvement of this performance is achieved by thermochemical treatment in a regulated gas atmosphere and cooling according to a special schedule. Normal electrocorundum during heat treatment in an oxidizing atmosphere changes the structural characteristics due to the decomposition of a solid solution of Ti_2O_3 in α-Al_2O_3 by oxidation to TiO_2. The formation of a block grain structure with microcracks increases the probability of chipping during the grinding tool operation and the appearance of new cutting surfaces.