添加Sc和提高Zn含量对7085铝合金力学性能、淬火敏感性和耐蚀性能的影响  

Effects of Sc addition and increasing Zn content on mechanical properties,quenching sensitivity and corrosion resistance of 7085 aluminum alloy

作　　者：孙浩鸣 刘崇宇[1] 石磊 张磊 肖济金 Sun Haoming;Liu Chongyu;Shi Lei;Zhang Lei;Xiao Jijin(College of Materials Science and Engineering,Guilin University of Technology,Guilin Guangxi 541004,China)

机构地区：[1]桂林理工大学材料科学与工程学院,广西桂林541004

出　　处：《金属热处理》2023年第4期196-203,共8页Heat Treatment of Metals

基　　金：广西自然科学基金(2022GXNSFAA035580)。

摘　　要：在7085铝合金基础上添加Sc和提高Zn含量制备了3种不同成分的热轧薄板样品,在470℃加热1 h后分别风冷(FC)和水冷(WC)淬火,然后进行120℃×24 h人工时效。再采用室温拉伸和晶间腐蚀试验及光学显微镜和透射电镜观察等试验方法,研究Sc和Zn对7085铝合金力学性能和耐蚀性能的影响。结果表明,添加Sc可以显著细化晶粒、钉扎位错、抑制再结晶、提高形核率、降低晶界无沉淀析出带的宽度及晶界析出相尺寸,从而有利于提高合金的强度与耐蚀性能,淬火敏感性也有所提高。在含Sc的基础上进一步提高Zn含量会使淬火诱导相的析出驱动力增大,晶内析出相和晶界析出相的数量增加,时效后合金的强度进一步提高,淬火敏感性显著增强,耐蚀性能有所下降。Three kinds of hot-rolled sheet specimen with different compositions were prepared by adding Sc and increasing Zn content on the basis of the 7085 aluminum alloy.After being heated at 470℃for 1 h,the specimens were quenched by force air-cooling(FC)and watercooling(WC)respectively,and then artificially aged at 120℃for 24 h.Then the effects of Sc and Zn elements on mechanical properties and corrosion resistance of the 7085 aluminum alloy were studied by room temperature tensile and intergranular corrosion tests,metallographic microscope observation and transmission electron microscope observation.The results show that the addition of Sc element can significantly refine the grain size,pin the dislocations,inhibit the recrystallization,increase the nucleation rate and reduce the width of the precipitation-free zone and the size of the precipitation phase on the grain boundary,thus contributing to the improvement of strength and corrosion resistance of the alloy,but the quenching sensitivity is increased.Further increase of Zn content on the basis of Sc addition will enhance the precipitated driving force of quench-induced phase,increase the number of intragranular and grain boundary precipitated phases,further improve the strength of the alloy after aging,significantly increase the quenching sensitivity and decrease the corrosion resistance.

关 键 词：7085铝合金 SC 力学性能 淬火敏感性 晶间腐蚀 

分 类 号：TG146.21[一般工业技术—材料科学与工程]