启锻时间对铸锻复合成形6061合金组织和性能的影响

Microstructure and Mechanical Properties of 6061 Aluminum Alloy Prepared by Casting-Forging Integrated Technology under Varied Forging-Starting Time

研究了启锻时间对铸锻复合一体化成形6061变形铝合金的组织和力学性能的影响。结果表明，不同启锻时间下铸坯靠近锻头处存在明显的流线变形组织，铸坯中间最后凝固部分组织则被压扁压实；当启锻时间为3~4 s时，施加的锻压力能有效对凝固铸坯进行压力补缩和组织密实并使其产生塑性变形，避免了缩孔、裂纹和组织疏松等缺陷出现；随着启锻时间的延长，热处理前后的铸锻件的抗拉强度和伸长率皆先增大然后趋于平缓减小，当启锻时间为4 s时，抗拉强度分别达到211.1 MPa和368.9 MPa，伸长率则分别达到17.6%和11.5%。

Microstructure and mechanical properties of 6061 wrought aluminum alloy prepared by castingforging integrated technology at different forging-starting time were investigated. The results show that forging integrated technology at different forging-starting time were investigated. The results show that the streamline deformation structure at different forging-starting time can be observed in the parts near to the forged head, while the final solidification structure at the middle is flatted and compacted. With the forging-starting time of 3 -4 s, the forging force can effectively exert pressure feeding, and make structure compact to eliminate the shrinkage, crack and loose structure. With the increase of forging-starting time, the curves of the tensile strength and elongation for the alloy both before and after heat-treatment are firstly increased remarkably, and then decreased gradually. Tensile strength of the alloy before and after heat treatment reaches 211.1 MPa and 368.9MPa, respectively, and the elongation reaches 17.57% and 11.5%, respectively, at the forging-starting time of 4 s.