Effects of Ce-La Addition on Microstructure and Mechanical Properties of Al-Si-Cu-Mg-Ni Alloy for Automobile
Different amounts of Ce-La complex rare earths were added to Al-Si-Cu-Mg-Ni alloys.The effects of different Ce-La composite rare earth additions on the microstructure and mechanical properties of as-cast Al-Si-Cu-Mg-Ni alloy were investigated by microstructure observation and mechanical properties test.The results show that a large number of massive primary Si phase and acicular eutectic Si phase exist in Al-Si-Cu-Mg-Ni alloy without rare earth.The primary Si phase diameter and eutectic Si phase size decrease first and then increase with the increase of Ce-La composite rare earth content.The primary Si phase diameter and eutectic Si phase size of the alloy are the smallest when Ce-La rare earth content is 0.4wt%.With the increase of Ce-La,the tensile strength and elongation of Al-Si-Cu-Mg-Ni alloy firstly increase and then decrease.When the Ce-La composite rare earth content is 0.4wt%,the tensile strength and elongation of Al-Si-Cu-Mg-Ni alloy reach the maximum value,which are 296.5 MPa and 2.9%respectively.