施压熔体温度对挤压铸造Al-5.0Cu-0.6Mn-0.5Fe合金组织和性能的影响

Effects of Squeezing Melt Temperature on Microstructure and Mechanical Properties of Al-5.0Cu-0.6Mn-0.5Fe Alloy Prepared by Squeeze Casting

采用拉伸性能测试、定量金相分析、扫描电镜等手段,研究施压熔体温度对挤压铸造Al-5.0Cu-0.6Mn-0.5Fe-0.1Ti-0.1RE合金微观组织和力学性能的影响。结果表明,在547~650℃的液固两相区,随着施压熔体温度的升高,合金的抗拉强度和伸长率缓慢增加。当施压熔体温度为650℃时,合金获得较高的综合力学性能,抗拉强度为299 MPa,伸长率达到17.5%。这主要与压力下发生凝固的液相增多导致的α-Al二次枝晶间距、第二相体积分数、铸造缺陷体积分数减小,以及"双峰组织"中的小晶粒组织体积分数增大有关。

Effects of squeezing melt temperature on microstructure and mechanical properties of Al-5.0 Cu-0.6 Mn-0.5 Fe-0.1 Ti-0.1 RE alloy prepared by squeeze casting were investigated by tensile test,image analysis and scanning electron microscope.The results show that with the squeezing melt temperature of650 ℃,the ultimate tensile strength and elongation of the alloy reach 299 MPa and 17.5%,respectively,while those of the alloy are increased slightly with the squeezing melt temperature from 590 ℃ to650 ℃,which can be attributed to the decrease of the dendritic arm spacing ofα-Al phase,the second intermetallic phases,the volume of casting defects and the increase of volume fraction of fine structure in bi-modal structure resulted from the increase of solidification liquid phase under applied pressure.