最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

The effect of rare earth metals on mechanical and corrosion properties of 7085 aluminum alloy（Al-7.5Zn-1.5Mg-1.4Cu-0.15Zr）was investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Inter granular, exfoliation corrosion, hardness, tensile test and electrical conductivity test were performed on both Al alloys with and without rare earth additives. It was shown the Al alloys with rare earth metals are presenting better mechanical properties such as higher strength and hardness as a result of finer microstructure in comparison with those without the additives, and the electrical conductivity was slightly lower. The corrosion resistance was greatly improved after adding rare earth metals. Where inter granular corrosion resistance was enhanced from Level IV to Level II, the denudation level for 48h was improved from EB to PA and ISSRT reflecting stress corrosion resistance was enhanced from 65% to 96%.