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.
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)
出处
《材料导报》
CSCD
北大核心
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)。
关键词
镁合金
深冷处理
非平衡凝固
时效析出
magnesium alloy
cryogenics
non-equilibrium solidification
aging precipitation
