The plasma-spark production of the mullite‒TiC‒ ZrC ceramic materials and investigation of their properties

Abstract

The phase compositions of the synthesized titanium carbide TiC and zirconium carbide ZrC powders are given in the article. The development of the crystalline phases, microstructure, relative density, open porosity, linear shrinkage, hardness, compression strength for the plasma-spark mullite‒TiC‒ZrC samples sintered at 1200‒1500 °С with various TiC to ZrC ratio was given. The synthesized TiC and ZrC powders are specified by the intensive TiC and ZrC phase's crystallization. The sintered samples with various TiC to ZrC ratio are characterized by the advanced mullitization within 1200‒1500 °С as well as by the slow TiC and ZrC phase's development up to 1500 °С. Over 1500 °С either the TiC or the ZrC phase  is in progress depending on the proportion of TiC and ZrC in the sintered materials. The samples with the higher TiC concentration have the closer sintered microstructure compared to that in the samples containing more of ZrC. This provides the elevation of
both the relative density and linear shrinkage, and the decreasing of the open porosity. Also this forms the harder samples with the equal indentations which don't create any damage, the samples having the maximum compressing strength. Ill. 6. Ref. 11. Tab. 1.