PROPERTIES ASSESSMENT IN WIZRC COMPOSITE FABRICATED THROUGH HOT-PRESS AND REACTION SINTERING

In this study the WIZrC composite fabricated via hot-press and reaction sintering of two precursors, conventional ZrO/WC and novel ZrSiO4/WC, has been compared with each other. At first W and ZrC powders were hot-pressed and after that WC/ZrO, and WC/ZrSiO, mixture were reaction sintered to produce the composite. The mechanical properties of produced composites including the density, hardness, modulus of elasticity and flexural strength were evaluated to compare the processes. The results show that the W-ZrC composite fabricated through hot-press, possesses better density and mechanical properties, however the cost of process in reaction sintering of WC/ZrSiO4 is much cheaper. Since reactivity is the main problem in sintering of micronized powders, the starting powders were selected in nano size as well to see the difference. In the case of using nano powders the amount of unreacted and unwanted phases reduced and the reaction progressed better.

Keywords:

WZrC composite , Hot pressing , Reaction Sintering , Nano powders