均匀化热处理对易切削Zn-10Al-1.0Cu-0.1Bi-0.1Sn变形合金组织与性能的影响

对自行研制的易切削Zn-10Al-1.0Cu-0.1Bi-0.1Sn变形合金铸态样品进行均匀化热处理,并采用力学性能测试、扫描电镜分析、钻削试验等手段,研究了热处理对该合金显微组织与力学性能和切削性能的影响。结果表明,试验合金铸态组织中存在较严重的枝晶偏析及非平衡共晶组织,经均匀化退火后,枝晶偏析和非平衡β+η共晶组织基本消除,组织分布更加均匀;其中经360℃保温12 h炉冷热处理后合金的抗拉强度降低,伸长率升高53.94%,塑性明显提高,有利于后续的热塑性加工;均匀化热处理对合金的切削性能影响不大。

Effect of homogenization treatment on microstructure and properties of a free-cutting wrought alloy Zn-10Al-1.0Cu-0.1Bi-0.1Sn

Effect of homogenization heat treatment on the microstructure and mechanical properties and cutability of a self-developed free-cutting wrought alloy Zn-10Al-1.0Cu-0.1Bi-0.1Sn was investigated by means of mechanical tests,scanning electron microscopy and drilling tests.The results show that it exists sever dendritic segregation and obvious non-equilibrium eutectic structure β+η in as-cast condition alloy.But the dendritic segregation and non-equilibrium eutectic structure are almost dissolved after homogenizing annealing,with more homogeneous microstructure obtained.Compared with the as-cast condition,the tensile strength of alloy heating at 360 ℃ for 12 h is decreased a little after heat treatment,and the elongation is increased by 53.94%,the plasticity is increased apparently,which helps the following thermoplastic process.And homogenization treatment has little effect on the cutability of the alloy.