Sintering Behavior of Green Compacts of Si and B₄C Mixed Powder in Nitrogen

Abstract

The Sintering Behavior of powder mixture compacts of Si and B₄C in nitrogen atmosphere at 1350°C was investigated. Mainly, Si was changed into α-Si₃N₄ and β-Si₃N₄ by a reaction with nitrogen, and B₄C was changed into BN and C, and C was converted into β-SiC by a reaction with Si. BN seemed to have an effect on reducing the number of pores in the nitrided body. B₄C retarded nitridation of Si. An Si-B-C-N-O layer and BN were formed on the surface of unnitrided Si particle in the nitrided body. An SiO₂-B₂O₃ layer formed on the surface of the Si particle in the nitriding stage seemed to retard nitridation of Si.