深冷处理对快冷Mg-6Al-1Y合金等温时效析出的影响  

Effect of Cryogenics on Isothermal Aging of Rapidly Cooled Mg-6Al-1Y Alloy

作　　者：刘灵 杨伟 吴宗锴 徐勇 余欢 LIU Ling;YANG Wei;WU Zongkai;XU Yong;YU Huan(National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室,南昌330063

出　　处：《材料导报》2023年第12期186-190,共5页Materials Reports

基　　金：国家自然科学基金(52061032,51461032);江西省教育厅资助项目(GJJ180513)。

摘　　要：采用铜模喷铸与等温时效相结合,探讨了深冷处理对非平衡凝固Mg-6Al-1Y合金组织及其沉淀析出行为的影响。结果表明,原始快冷合金的凝固组织由细小不发达花瓣状α-Mg基体相、晶界离异共晶β相和Al2Y稀土相所组成。深冷过程中引起的微应力及塑性变形有利于凝固组织细化,同时形成高密度位错结构。经250℃/4 h时效处理后,快冷合金的晶界处发生不连续沉淀,所析出的针片状β相择优生长,并与基体保持良好的共格关系。深冷处理有效促进快冷合金中β相的析出,有利于晶内连续沉淀形成并改善析出相形貌为短棒状,合金显微硬度高达77.2HV,相比原始快冷合金提高23.1%。Effects of cryogenics on microstructure and subsequent precipitation behavior of non-equilibrium solidified Mg-6Al-1Y alloy were investigated by spray casting and aging treatment.The results show that the microstructure of quenched alloy is composed of fineα-Mg grain with undeve-loped petal-like shape,divorced eutecticβphase at grain boundary and Al2 Y rare earth phase.The micro-stress and plastic deformation arising from cryogenics are beneficial to the grain refinement and formation of high density dislocation structure.After aging with 250℃/4 h,discontinuous precipitation occurs at the grain boundary of quenched alloy,accompanied by the preferential growth of needle-plateβphase with ideal coherent relationship with the matrix.Cryogenics accelerates the precipitation ofβphase,and favors the continuous precipitation at grain interior with short rod-like shape.The resultant hardness reaches 77.2HV,which is 23.1%higher than that of the initial rapidly cooled alloy.

关 键 词：镁合金 深冷处理 非平衡凝固 时效析出 

分 类 号：TG146.2[一般工业技术—材料科学与工程]