Abstract
Vacuum diffusion bonding of SiC ceramic to Ni–25 at.-%Cr alloy was carried out at 1223–1323 K for 0.9–3.6 ks under a pressure of 7.2 MPa. The kinds of the reaction products and the interface structures of the joints were investigated by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and X-ray diffraction (XRD), and the kinetic parameters describing the growth of reaction layers were calculated. The experiment and analysis identify that four kinds of reaction products, namely Ni2Si, graphite (G), Ni5Cr3Si2 and Cr3Ni2SiC, have formed during the diffusion bonding of SiC ceramic to Ni–25 at.-%Cr alloy. The interface structure of the SiC/Ni–Cr joints is SiC/(Ni2Si+G)/(Cr3Ni2SiC + Ni5Cr3Si2)/Ni5Cr3Si2/Ni- Cr, and each reaction layer in this structure grows according to a parabolic law. The activation energies for growth of (Ni2Si+G), (Cr3Ni2SiC+Ni5Cr3Si2), and Ni5Cr3Si2 are 217, 248, and 233 kJ mol 1, respectively.