成形工艺对Mg-Sn-Al-Zn-Si合金组织性能的影响

Effects of Forming Technology on Structure and Properties of Mg-Sn-Al-Zn-Si Alloy

将铸态Mg-5Sn-1.5Al-1Zn-0.8Si镁合金进行单向挤压和往复挤镦变形,采用OM、SEM等分析合金组织,采用拉伸实验测定合金力学性能。结果表明:单向挤压组织中的合金相分布较均匀,其晶粒比铸态合金的晶粒细小,挤压态试样的抗拉强度、延伸率分别比铸态合金提高31%和11.9%。相对于单向挤压工艺,往复挤镦时挤压力明显增大,与原始铸态和单向挤压试样相比,往复挤镦合金的晶粒更细小,组织更均匀,其抗拉强度、延伸率比铸态分别提高106%和270%。

As-cast Mg-5Sn-1.5Al-1Zn-0. 8Si magnesium alloy was processed by unidirectional extrusion （UE） and reciprocating extrusion-upsetting （REU） techniques. Microstructure of the alloy was studied with OM, SEM, and mechanical properties with tensile test. The results indicate that alloy phase distributes equably in the unidirectionally extruded structure, with finer grain size than that of the cast alloy. The tensile strength and elongation of the extruded specimen are 31% and 11.9%, respectively, higher than those of the cast alloy. In comparison with the unidirectional extrusion, reciprocating extrusion-upsetting technique has gotten an obvious increased extrusion force. While compared with the original cast and unidirectional extrusion alloys, the reciprocating extrusion-upsetting alloy has finer grains size and more homogeneous microstructure, with tensile strength and elongation 106% and 270%, respectively, higher than those of cast alloy.