Effect of Heat Input on Interfacial Microstructure and Mechanical Properties of 316L/CuCrZr Multimaterial Fabricated by Pulsed WAAM

Copper‐steel multimaterials have been applied in various fields due to their excellent comprehensive properties. Pulsed wire arc additive manufacturing (WAAM) is an efficient method for fabricating multimaterials, and its low heat input characteristics can effectively suppress the formation of metallurgical defects at the copper‐steel interface. This study investigated the interfacial microstructure and mechanical properties of 316L/CuCrZr specimens under different heat inputs. The results indicated that a dual‐phase structure consisting of Fe‐rich phase and Cu‐rich phase was formed in the fusion zone. With decreasing heat input, the width of the fusion zone progressively decreased, and the element segregation behavior became more pronounced. Furthermore, reducing heat input effectively improved the mechanical properties in both horizontal and vertical directions. The horizontal 316L/CuCrZr composite exhibited 477 ± 5 MPa strength and 51.4% ± 1.7% elongation (EL), with a 54.2% increase in EL. The grain refinement of the CuCrZr deposited layer was responsible for the improvement in mechanical properties in the vertical direction. The optimal tensile strength and EL in the vertical direction were 200 ± 3 MPa and 17.5% ± 0.5%, respectively, representing increases of 18.7% and 23.5%, respectively. This study provides valuable guidance for the fabrication of 316L/CuCrZr composite materials by WAAM.