Analysis of Mechanical Properties of IN 718 Produced by Cold Metal Transfer

Abstract

Wire Arc Additive Manufacturing (WAAM) has emerged as a promising technology for the fabrication of large-scale metallic components due to its high deposition rate and efficient material utilization. Among various WAAM approaches, the Cold Metal Transfer (CMT) process is characterized by reduced heat input, stable arc behavior, and low spatter generation, making it particularly suitable for processing nickel-based superalloys. In this study, Inconel 718 components were fabricated using the WAAM-CMT technique and systematically compared with conventionally manufactured reference material. The investigation focused on the relationship between processing conditions, microstructural evolution, defect formation, and resulting mechanical properties in the as-deposited state as well as after post-processing, including Hot Isostatic Pressing (HIP) and subsequent heat treatment. The results indicate that WAAM-CMT processing leads to reduced mechanical performance in the as-built condition (Rm ≈ 550-720 MPa). However, the application of HIP combined with optimized heat treatment significantly improves the mechanical properties through defect elimination, microstructural homogenization, and precipitation strengthening (Rm ≈ 1100-1250 MPa). As a result, the mechanical performance of the processed material approaches or even exceeds that of the reference material.