Gas Atomized Nickel-based Alloy Powders from Recycled Casting Scraps and Remanufacturing of IN713LC Castings

Abstract

Gas atomization of recycled Inconel 713LC (IN713LC) casting scrap was studied to produce feedstock powders for laser additive manufacturing. Nickel-based alloy powders and the laser metal deposition (LMD) process are used to remanufacture IN713LC castings to repair casting defects and improve the yield of castings. The material characteristics of nickel-based alloy powder and the microstructure of LMD castings were investigated. The effect of aging treatment on the microstructure and hardness of the repaired area is also discussed. The experimental results show that IN713LC alloy powders of 50~120 μm are suitable for LMD coating at 500-700W laser power. The fine microstructure of LMD layer is a mixed structure with both columnar and equiaxed grains. There is a good interface between the LMD layer and the casting substrate, no voids or cracks were observed. After aging treatment, fine γ’ precipitates are precipitated in the austenite matrix of the LMD layer, so its microhardness can be increased to more than 387 Hv.