Investigation of micromechanical properties of fused alumina and silicone carbide grains

Abstract

Micromechanical properties of abrasive material grains of fused alumina and silicone carbide are investigated applying the microindentation method. Such parameters as microhardness, microbrittleness, and microstrength were evaluated depending on the penetration depth of the Vickers diamond pyramid to the 0.5 — 5.0 µm thick surface under analysis. The microhardness parameter is the stress required for formation of a brittle failure area within the pyramid imprint. The microbrittleness criterion defines the ratio of the brittle failure area within the imprint and the imprint area. The power-law dependence of the parameters on the pyramid penetration depth is established: the lower the depth, the higher are microhardness and microstrength, yet the lower is microbrittleness. The obtained results enable creation of a standard basis, forecasting of the performance level of abrasive tools, refractory and wear-resistant items, filters, and special ceramics.

Effect of Heat Treatment on Structural and Mechanical Properties of Alloyed Fused Alumina

“…Cr-Ti fused alumina (samples 4, 5, and 6) after high-temperature heating behaves variously, depending on the Ti 3+ content in the solid solution: the structure of brown grains (the ratio in the TiO2/Cr2O3 solid solution ≥ 1.5) becomes more balanced; as for purple grains (TiO2/Cr2O3 ≤ 1.5), defects are distributed non-uniformly, so the structure remains unbalanced similarly to Cr alumina. The study revealed higher values of Cr-Ti fused alumina micromechanical parameters [4,7,8,9], besides, purple grains have the maximum values; such Cr-Ti fused alumina reaches the maximum values of micro hardness and crack resistance after heat treatment at 1250 °C.…”