Effects of Cd addition in welding wires on microstructure and mechanical property of wire and arc additively manufactured Al-Cu alloy
(1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education,Tsinghua University, Beijing 100084, China;
3. Capital Aerospace Machinery Corporation Limited, Beijing 100076, China;
4. State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China)
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education,Tsinghua University, Beijing 100084, China;
3. Capital Aerospace Machinery Corporation Limited, Beijing 100076, China;
4. State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China)
Abstract: Wall structures were made by cold metal transfer-based wire and arc additive manufacturing using two kinds of ER2319 welding wires with and without Cd elements. T6 heat treatment was used to improve mechanical properties of these wall structures. Due to the higher vacancy binding energy of Cd, Cd-vacancy clusters are formed in the aging process and provide a large number of nucleation locations for θ′ phases. The higher diffusion coefficient of the Cd-vacancy cluster and the lower interfacial energy of θ′ phase lead to the formation of dense θ′ phases in the heat-treated α(Al). According to the strengthening model, after adding Cd in ER2319 welding wires, the yield strength increases by 43 MPa in the building direction of the heat-treated wall structures.
Key words: Cd; welding wire; wire and arc additive manufacturing; Al-Cu alloy