预时效工艺对7020铝合金显微组织和应力腐蚀性能的影响
发布人：上海艾荔艾合金股份有限公司www.shailiai.cn
更新时间：2016-06-03
7020铝合金经470 ℃固溶1 h后分别进行自然时效0 h、168 h以及65 ℃预时效72 h、168 h，再进行(90 ℃，8 h)+(160 ℃，14 h)双级时效。采用室温拉伸、慢应变速率拉伸(SSRT)、扫描电镜(SEM)、透射电镜(TEM)研究预时效工艺对7020铝合金的常温拉伸性能、抗应力腐蚀性能与显微组织的影响。
预时效工艺对7020铝合金显微组织和应力腐蚀性能的影响Effect of pre-aging on microstructure and stress corrosion resistance of 7020 aluminum alloy7020铝合金经470 ℃固溶1 h后分别进行自然时效0 h、168 h以及65 ℃预时效72 h、168 h，再进行(90 ℃，8 h)+(160 ℃，14 h)双级时效。采用室温拉伸、慢应变速率拉伸(SSRT)、扫描电镜(SEM)、透射电镜(TEM)研究预时效工艺对7020铝合金的常温拉伸性能、抗应力腐蚀性能与显微组织的影响。结果表明:经65 ℃、168 h预时效处理后，合金具有最高的抗拉强度Rm=397.4 MPa和最好的抗应力腐蚀性能ISSRT=-0.003; 65 ℃、72 h预时处理效和自然时效168 h后合金的抗拉强度和抗应力腐蚀性能相当，Rm、ISSRT分别为387.6 MPa、0.034和392.0 MPa、0.036;而直接双级时效合金的抗拉强度和抗应力腐蚀性能最差，Rm、ISSRT为368.9 MPa、0.038。晶内析出相η′(MgZn2)的尺寸随预时效时间的延长而减小，晶界析出相η(MgZn2)的断续分布程度随预时效时间延长而增大。
After solution heat treatment at 470℃ for 1h, the alloys were natural aged for 0 h or 168 h and pre-aged at 65 ℃ for 72 h or 168 h, respectively. And then, the two-step aging ((90 ℃, 8 h)+(160 ℃, 14 h)) was conducted on these alloys. The effect of pre-ageing treatment on the tensile properties, resistances to stress corrosion and microstructures of 7020 aluminum alloy was investigated by tensile test, slow strain rate tensile (SSRT) test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). 7020 aluminum alloy aged at 65 ℃ for 168 h pre-ageing treatment has the highest tensile property Rm of 397.4 MPa as well as the best stress corrosion resistance ISSRT of -0.003. The tensile property and stress corrosion resistance of alloy pre-ageing treatment at 65 ℃ for 72 h are 387.6 MPa and 0.034. And it is comparable of that of natural aging 168h, with Rm of 392.0 MPa and ISSRT of 0.036. While the tensile property and stress corrosion resistance of alloy by direct two-step aging are the worst, with Rm of 368.9 MPa and ISSRT of 0.038. With the increase of the pre-aging time, the size of intragranular precipitates η′(MgZn2) inside grains decreases, the intermittent distribution degree of precipitates intragranular precipitates η′(MgZn2) inside grains decreases and the intermittent distribution degree of precipitates η(MgZn2) at the grain boundaries increases.
作为值得信赖的合作伙伴和高品质金属合金的半成品供应商，艾荔艾拥有完善的服务体系和专业的团队。在同客户交易的过程中，我们力求根据不同的应用需求将我们的产品做到精益求精。针对当前和未来的市场需求，艾荔艾致力于为客户提供最佳的金属材料解决方案。
AILIAI
has been a reliable partner and supplier of sophisticated and high-quality
semi-finished products maed of alloys. In dialogue with our customers, we
optimise our products to meet the specific application requirements. AILIAI
develops the best alloy material solutions for current and future
challenges.
获取更多我们供应的合金和服务信息，请致电086-021-67660801或发电子邮件kefu@ailiaigroup.com联系我们，您也可以通过微博，微信，领英，XING，脸书和推特与我们互动。
For
more information on the alloys and services that we supply, call
us at
086-021-67660801 or email us at kefu@ailiaigroup.com. You can also get in touch
on social media, we are constantly active on Weibo, Weixin, LinkedIn, XING, Facebook and Twitter.