铝合金连续进给搅拌摩擦增材制造技术

为解决固相增材制造过程送料不连续及层间界面弱连接的难题，提出了连续进给搅拌摩擦增材制造的方法，设计了一个带孔的储料腔和一个可对丝材进行热塑化并连续挤压的螺杆拓扑结构搅拌头. 结果表明，Al-Si合金丝材经由送丝孔进入储料腔，搅拌头连续热塑化并向下挤压材料，搅拌针在堆积层间的搅拌作用有效地提高了堆积层间的界面结合能力，成功实现了铝合金连续进给搅拌摩擦增材制造成形并解决了层间界面弱连接的难题. 单层增材制造堆积层厚度平均为1.2 mm，Al-Si合金增材制造成形件沿堆积方向的抗拉强度和断后伸长率分别为207.1 MPa ± 3.2 MPa和19.6 % ± 5.3%，该技术为实现大型铝合金构件全固相增材制造提供了一种可行性方案.

Aluminum alloy friction stir additive manufacturing technique with continuous feedstocks

In order to solve the inherent issues of discontinuous feedstocks and kiss bonding in the solid-state additive manufacturing process, a novel friction stir additive manufacturing with continuous feedstocks was proposed. The applied tools including a storage cavity with a feeding hole and a screw topology which can thermo-plasticize and continuously extrude the Al-Si alloy wire were designed. The results showed that the Al-Si alloy wire was conveyed to the feeding hole into the storage cavity, and the pin continuously thermo-plasticized and extruded downward Al-Si alloy materials. The probes at the bottom of the pin were used to stir and process the thermo-plasticized materials, which can extremely improve the bonding efficiency of the interfaces. The friction stir additive manufacturing with continuous feeding aluminum alloy wires was successfully realized, and the inherent issue of kiss bonding of interfaces between layers was solved. The thickness of the individual layer was about 1.2 mm. The tensile strength and elongation of the Al-Si alloy formed part along the stacking direction have little differences, which were 207.1 ± 3.2 MPa and 19.6 ± 5.3%, respectively. Friction stir additive manufacturing with continuous feedstocks can provide a feasible process method towards full solid-state additive manufacturing of large aluminum alloy parts.