Interface microstructure and mechanical properties of wire-laser directed energy deposited Inconel 718 on CuCrZr substrate

In this article, Inconel 718 was fabricated on the CuCrZr substrate with cold-sprayed intermediate layer using wire-laser directed energy deposition. The interface microstructure and mechanical properties of IN718/CuCrZr bimetallic structure were examined for both as-deposition and heat treatment conditions. It was found that IN718/CuCrZr interface exhibited sound metallurgical bonding without defects. Fine equiaxed grain zone with the average grain size of 1.3 ± 0.6 μm was observed at as-deposited interface and broadened after heat treatment. Hardness and elongation of the IN718/CuCrZr interface enhanced upon heat treatment. Remelting and rapid solidification of the grain edges near the interface contributed to wider fine grain zone. Precipitation strengthening of Cr phase generated by heat treatment led to the increment of mechanical properties of interface region.