Wire arc additive manufacturing of Al-Si-Mg aluminum alloy through wire-powder synchronous deposition
(1. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China;
2. Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
3. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China)
2. Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China;
3. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China)
Abstract: Owing to the lack of matching commercial welding wires, the development of wire arc additive manufacturing (WAAM) for most aluminum alloys is hindered. A wire-powder synchronous arc additive manufacturing (WPAAM) was proposed to prepare the target Al-Si-Mg aluminum alloy. Based on the synchronous deposition of AlSi12 wire and pure Mg powder, the deposition width of the WPAAMed thin-wall was increased by 61% compared with that of WAAMed thin-wall using AlSi12 wire, and the machining allowance was reduced by 81%. The added Mg powder benefited to form refined equiaxed grains, and reduced the average grain size of the WPAAMed thin-wall to 47.1 μm, showing a decrease of 23.8% relatively to that of the WAAMed thin-wall. Besides, Mg reacted with Si to form Mg2Si strengthening phases. The mechanical properties tests showed that the ultimate tensile strength and elongation of the WPAAMed thin-wall increased up to 174.5 MPa and 4.1%, reaching 92% and 60% those of the WAAMed thin-wall, respectively.
Key words: wire arc additive manufacturing; wire-powder synchronous deposition; Al-Si-Mg aluminum alloy; forming accuracy; mechanical properties