Mechanical Behavior and Microstructural Characterization of ZrB2-B4C-Mo Cermets Synthesized by Ball Milling

Abstract

The present paper deals with the study of mechanical behavior of ZrB2-B4C-Mo cermets where optimal composition consisting of ZrB2, B4C and Mo are respectively in proportion of 40, 40 and 20 (all in wt. %). For comparative study, the firing of cermest was done at 1500⁰C, 1600⁰C for 2hrs & 1800⁰C for 3 min in reducing atmosphere .The Vickers hardness test of the cermet fired at 1500⁰C & 1600⁰C shows hardness of 16GPa & 18GPa respectively whereas sample fired at 1800⁰C shows 32GPa. Similarly wear depth of sample fired at 1500⁰C & 1600⁰C shows higher mass loss than that of sample fired at 1800⁰C.This may be attributed to the formation of metastable phases like MoB, ZrC which densify the structure at 1800⁰C and strengthen the whole matrix.