电弧增材制造AZ31镁合金组织与力学性能分析

Microstructure and mechanical properties of wire arc additive manufacturing of AZ31 magnesium alloy

针对镁合金在轻量化结构件领域的应用前景,采用基于MIG焊的电弧增材制造工艺开展了两组不同路径的AZ31镁合金增材实验,并对其微观组织和力学性能进行了分析。结果表明:增材构件相较于原始焊丝的化学成分无较大变化;单道次多层往复堆积路径相较于多道次多层堆积路径,更易制得表面更为平整,内部更为致密的构件,其屈服强度为77.3 MPa,抗拉强度为235 MPa,达到原始焊丝75%的力学性能水平,平均显微硬度为52.7HV,断后伸长率最高达到了27%;增材构件拉伸断裂方式为韧性断裂,并在多道次多层往复堆积构件断口处发现其内部存在气孔。验证了电弧增材制造AZ31镁合金工艺的可行性。

For the application prospect of magnesium alloys in the field of lightweight structural parts,this study carried out two sets of additive tests of AZ31 magnesium alloys with different paths using wire arc additive manufacturing(WAAM)process based on MIG welding,and analyzed their microstructure and mechanical properties.Results show that the chemical composition of the additive components did not change significantly compared with the original welding wire.The components produced by single-pass multi-layer reciprocating path had smoother surface and denser interior than those produced by multi-pass multi-layer reciprocating deposition path.The yield strength of the components was 77.3 MPa,and tensile strength was 235 MPa,which was 75%of mechanical performance of the original welding wire;the average microhardness was 52.7HV,and the elongation after fracture was up to 27%.The tensile fracture mode of additive components was ductile fracture,and pores were observed in the fracture of the member obtained by multi-pass multi-layer reciprocating deposition.The feasibility of the arc additive manufacturing process of AZ31 magnesium alloy was verified.