Fast Densification of B_4C Ceramics with Al_2O_3 as a Sintering Aid by Spark Plasma Sintering

摘要

The densification behavior and mechanical properties of B_4C by SPS at 1900°C for 2 min with additions of Al_2O_3 up to 10 wt.% were investigated. When the additional of 10 wt.%, the relative density was 99% and the hardness went to 33GPa. Sinterability was greatly improved by the addition of a small amount of Al_2O_3, and the SPS technology with high hearing rate is particularly attractive for prepare of poorly sinterable materials. The improvement was attributed to the enhanced mobility of elements through the Al_2O_3 near the melting temperature. As a result of this improvement in the density, mechanical properties, such as hardness, fracture toughness, increased remarkably.