INTERFACIAL STRUCTURE AND PHASE REACTION IN SiC/NiCr ALLOY JOINT

Bonding of SiC to SiC using Ni and Ni - 25at%Cr foils was performed at high temperature.Interface structures and reaction phases were investigated by EPMA analyses and XRD diffraction method, re- spectively. At a bonding temperature of 1273K Ni reacts with SiC and forms various Ni silicides con- taining graphite baside SiC. Ni3Si without graphite was formed at Ni side.The interface structure of SiC/Ni joint was SiC/Ni2Si C/Ni31 Si12 G/Ni3 Si/Ni. At the interface between SiC and Ni- 25at%Cr alloy the Ni silicide was only Ni2Si at the same bonding temperature,and further(Cr, Ni)7 (Si, C)3 carbide was formed between Ni silicide graphite zone and Ni - 25at%Cr alloy.The interface structure of SiC/Ni - 25at%Cr alloy was SiC/Ni2Si C/(Cr, Ni)7 (Si, C)3 Ni(ss. Cr, Si)/Ni - 25at%Cr.