SiC/V接合層の構造と破断強度

Abstract

Pressureless-sintered (PLS) SiC was bonded to SiC using V foils by solid state bonding at 1373∼1673 K for 1.8∼64.8 ks and 30 MPa in vacuum. The interfacial reaction layers and microstructure were investigated by electron probe microanalysis and X-ray diffractometry. At 1573 K for 7.2 ks, granular V2C and V3Si layer zone were formed on the V and SiC side, respectively. A hexagonal V5Si3Cx phase was formed at the interface between V3Si and SiC at 1573 K for 7.2-14.4 ks, and the interface structure of the joint became SiC/V5Si3Cx/V3Si/V2C+V/V. With the further bonding at 1573 K, V was completely consumed, and the interface structure of the joint became SiC/V5Si3Cx/V3Si/V2C.The fracture shear strength of the SiC/V/SiC couples bonded at 1573 K for 14.4 ks, comprized a thin layer of V5Si3Cx adjacent to SiC and showed a maximum of 130 MPa at room temperature and exhibited stable strength at the temperatures up to 1073 K.