钪锆复合添加对Al-Zn-Mg合金淬火敏感性的影响  

Effects of combined additions of Sc and Zr on quenching sensitivity of Al-Zn-Mg alloy

作　　者：刘贇 黄继武[1] 邓英[1] 江福清 王英君[2] Liu Yun;Huang Jiwu;Deng Ying;Jiang Fuqing;Wang Yingjun(School of Materials Science and Engineering,Central South University,Changsha Hunan 410083,China;Northeast Light Alloy Co.,Ltd.,Harbin Heilongjiang 150060,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]东北轻合金有限责任公司,黑龙江哈尔滨150060

出　　处：《金属热处理》2018年第11期20-25,共6页Heat Treatment of Metals

基　　金：国家自然科学基金(51601229);广东省科技计划项目(2016B090931004);湖南省自然科学基金(2016JJ3151)

摘　　要：以Al-5. 7Zn-2. 0Mg和Al-5. 7Zn-2. 0Mg-0. 10Sc-0. 10Zr（wt%）合金为研究对象,通过分级淬火方法,获得两种合金的时间-温度-性能（TTP）曲线,结合淬火因子分析法及电子显微分析技术,对比研究了钪锆复合添加对铝锌镁合金淬火敏感性的影响。结果表明：Al-Zn-Mg和Al-Zn-Mg-Sc-Zr合金的鼻尖温度分别为300℃和290℃,淬火敏感区间分别为230～350℃和170～380℃,临界淬火速率分别为2℃/s和8℃/s。钪锆添加提高铝锌镁合金淬火敏感性的原因主要为：在淬火连续冷却过程中,当淬火冷却速度较慢时,Al-Zn-Mg-Sc-Zr合金存在的纳米级Al3（Sc,Zr）粒子会成为粗大时效相η（MgZn2）的异质形核中心,降低了过饱和固溶体的稳定性。Time-temperature-properties（TTP）curves of two alloys（Al-5.7Zn-2.0Mg and Al-5.7Zn-2.0Mg-0.10Sc-0.10Zr）were obtained by step quenching.Meanwhile,effect of adding extra Sc and Zr on quenching sensitivity of the Al-Zn-Mg alloy was investigated by electronic microanalysis and quench factor analysis.The results indicate thatnose temperature ofthe Al-Zn-Mg alloy,quenching interval and critical quenching speed are 300℃,230-350℃ and 2℃/s,respectively.The corresponding data of the Al-Zn-Mg-Sc-Zr alloy are 290℃,170~380℃and 8℃/s,respectively.The main reasons for improving the quenching sensitivity of Al-Zn magnesium alloy by adding scandium and zirconium are during the continuous cooling process,the nanoscaled Al3（Sc,Zr）particles in the Al-Zn-Mg-Sc-Zr alloy will become the heterogeneous nucleation core of the coarsephaseη（MgZn2）when the cooling rate is relatively slow,and the stability of supersaturated solid solution is reduced.

关 键 词：AL-ZN-MG合金 TTP曲线 淬火因子分析法 Al3(Sc Zr)粒子 

分 类 号：TG146.2[一般工业技术—材料科学与工程]