This study evaluated homogenizing process of alloying elements such as aluminum, titanium and chromium during Transient Liquid Insert Metal Diffusion Bonding (TLIM-bonding) of Ni-base superalloys such as MM007, Mar-M247, Inconel 713C and IN939 with a Ni-15%Cr-4%B amorphous insert metal.
The detailed analysis at the bonded interlayer of TLIM-bonded joint was performed quantitatively using electron probe microscopy (EPMA) technique. From the experimental results, the concentrations at the center of the bonded interlayer (Ct) of aluminum and titanium increased and that of chromium decreased dependent on the holding time during homogenizing process due to elements diffusion from the base metal to the bonded interlayer. Further, increasing temperature decreased the holding time for completion of homogenizing process.
Homogenizing process was calculated analytically by applying one-dimensional diffusion model considering the base metal dissolution, thereby equations were derived for estimating the concentration Ct of aluminum, titanium and chromium.
The calculated values corresponded well with the experimental ones, except in the early stage of homogenizing process. It follows that the equation by applying one-dimensional diffusion model can estimate the holding time for completion of homogenizing process in fabrication.
