快速凝固AlCrYZr合金组织性能的热稳定性研究  

Thermal Stabilities of Microstructures and Mechanical Properties of Rapidly Solidified AlCrYZr Aluminium Alloy

作　　者：肖于德[1] 黎文献[1] 李松瑞[1] 马正青 

机构地区：[1]中南工业大学,长沙410083

出　　处：《稀有金属材料与工程》2000年第1期21-24,共4页Rare Metal Materials and Engineering

基　　金：国家"九五"攻关项目! (95 YS 0 0 4 );国家"863"高技术项目 (863 715 )资助

摘　　要：采用金相、X射线衍射(XRD)、透射电镜(TEM)、硬度测定和拉伸试验研究了高温热暴露对快速凝固AlCrYZr合金显微组织影响和高温下力学性能的热稳定性,结果表明,快速凝固AlCrYZr合金主要第二相为Al20Cr2Y(立方,a=1437nm)和DO23Al3Zr(正方,a=04013nm,c=1732nm),Al20Cr2Y在500℃热暴露尚能保持其立方结构,但质点明显粗化,甚至块状化,在粗大的Al20Cr2Y相中存在有层错和孪晶结构。合金固溶体在退火过程中可能出现Ll2Al3Zr,硬度有所提高。从合金组织性能来看,实验合金至少在350℃以下可以稳定使用。Using of optical microscopy, X ray diffraction(XRD), transmission electron microscopy(TEM), hardness and tensile testing, the effect of thermal exposure at high temperatures on the microstructures and of high temperature tensile properties (including thermal stability) of rapidly solidified AlCrYZr have been studied. The results show that there are two main phases,Al 20 Cr 2Y(cubic, a =1 437 nm) and DO 23 Al 3Zr(terganal, a =0 4 013 nm, c = 1 732 nm), in the as solidified alloy. The Al 20 Cr 2Y phase can maintain its cubic structure at 500℃, but the particles coarsen remarkably and even become lumpish. In coarse lumpish Al 20 Cr 2Y phase the plane faults and twin structures exist. The hardness of the alloy increases during thermal exposure due to precipitation of Li 2Al 3Zr from the solid solution. The microstructural and tensile results indicate that the alloy may be used stably at least below 350℃.

关 键 词：快速凝固 铝合金 热稳定性 

分 类 号：TG146.2[一般工业技术—材料科学与工程]