Mechanical and electrical properties of MoSi2-based ceramics with various ZrB2-20 vol% SiC as additives for ultra high temperature heating element

摘要

MoSi2-(ZrB2-20 vol% SiC) ceramics were produced by pressureless sintering at 1700-1900 degrees C for 1 h. The amounts of ZrB2-20 vol% SiC were in the range of 0-80 vol%. Synergetic effects of ZrB2 and SiC additives on flexure strength of MoSi2 based ceramics were investigated in detail. A maximum strength of 279 +/- 20 MPa was examined for the ceramic with 20 vol% (ZrB2-20 vol% SiC). The electrical resistivity of the ceramics decreased with the volume fraction of (ZrB2-20 vol% SiC) increasing. Microstructure analysis and topological transformation calculations were carried out, which further proved the flexure strength and electrical resistivity measurement results.