Research on Microstructure and Properties of 6005 Al Alloy After Cryogenic Process

Before the single-stage aging at different temperatures,the 6005 aluminum alloy specimens were treated with water quenching and water quenching combined with cryogenic treatment.Then the effects of various heat treatment processes on the property of 6005 alloy were analyzed by means of metallographic observation,hardness test,tensile strength test and impact toughness test.The results show that cryogenic treatment can make 6005 aluminum alloy strengthening phase more homogeneous and smaller,and result in the formation of precipitations in the grain boundaries which can improve its hardness and strength,and reduce its ductility and toughness.The ideal aging temperature of cryogenic treated 6005 aluminum alloy is 165 ℃,and the hardness is 110 HB after 11 h aging.Compared with water quenching,the peak aging temperature increases 10℃and the hardness improves by 12.2%.