STRUCTURE AND STRENGTH OF SIC V BONDING INTERFACE/

Pressureless-sintered (PLS) SIC was bonded to SiC using V foils by sol id state bonding at 1373 similar to 1673 K for 1.8 similar to 64.8 ks and 30 MPa in vacuum. The interfacial reaction layers and microstructu re were investigated by electron probe microanalysis and X-ray diffrac tometry. At 1573 K for 7.2 ks, granular V2C and V3Si layer zone were f ormed on the V and SiC side, respectively. A hexagonal V5Si3Cx phase w as 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 consume d, and the interface structure of the joint became SiC/V5Si3Cx/V3Si/V2 C.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 s howed a maximum of 130 MPa at room temperature and exhibited stable st rength at the temperatures up to 1073 K.