Fe含量对挤压铸造Al-3.5Mg-0.8Mn合金组织性能的影响

采用拉伸和硬度测试、扫描电镜和X射线衍射仪等手段,研究了不同Fe含量对挤压铸造Al-3.5Mg-0.8Mn合金显微组织和力学性能的影响。结果表明,Fe能改善合金的力学性能,合金中只存在Al₆(FeMn)相。合金的抗拉强度和屈服强度随着Fe含量的增加而增大,伸长率随着Fe含量的增加而降低,原因是随着Fe含量增加,硬脆的Al₆(FeMn)相增多。在挤压压力为75MPa和Fe含量为0.5%时,合金的综合力学性能最佳,其抗拉强度为252MPa,屈服强度为128MPa,伸长率为28%。

Effects of Fe Content on Microstructures and Mechanical Properties of Squeeze Casting Al-3.5Mg-0.8Mn Alloys

The effects of Fe content on the microstructures and mechanical properties of squeeze casting Al-3.5Mg-0.8Mn alloys were analyzed by tensile and hardness test,scanning electron microscopy and X-ray diffraction.The results reveal that Fe can improve the mechanical properties,and only Fe-rich intermetallics of Al₆(FeMn)phases is observed in the alloy.The ultimate tensile strength and yield strength are improved by increasing Fe content,however the elongation is decreased due to the increase of brittle Al₆(FeMn)phases.With applied pressure of 75 MPa and the Fe mass fraction of 0.5%,the mechanical properties of the alloys present the satisfied effects,where ultimate tensile strength,yield strength and elongation reach 252 MPa,128 MPa and 28%,respectively.