热变形Ti-45Al-7Nb-0.3W合金的显微组织与力学性能  

Microstructure and Mechanical Properties of Hot Deformed Ti-45Al-7Nb-0.3W Alloy

作　　者：范爱一 李慧中[1,2,3] 梁霄鹏[1,2] 陈永辉[1] 齐叶龙 FAN Ai-yi;LI Hui-zhong;LIANG Xiao-Peng;CHEN Yong-hui;QI Ye-long(School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory for Powder Metallurgy,Central South University,Changsha 410083,China;Key Laboratory of Nonferrous Metal Materials Science and Engineering（Ministry of Education）,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学粉末冶金国家重点实验室,长沙410083 [3]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083

出　　处：《材料工程》2018年第7期121-126,共6页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51174233)

摘　　要：采用金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)和拉伸试验研究热变形(锻造、轧制)Ti-45Al-7Nb-0.3W(原子分数/%,下同)合金的显微组织与力学性能。结果表明:铸态Ti-45Al-7Nb-0.3W合金为近层片组织,主要由α2/γ层片晶团及分布在层片晶团周围的少量γ相和β相组成,层片晶团平均尺寸为100μm;经热包套锻造后,层片晶团发生破碎、扭折,并且室温抗拉强度较铸态提高了77MPa,800℃抗拉强度提高了36MPa;该锻态合金经热包套轧制后,合金组织转变为细小的双态组织,平均晶粒尺寸为25μm,合金力学性能进一步提高,其中室温抗拉强度提高到603MPa,伸长率为1.0%,800℃抗拉强度提高到716MPa,伸长率为3.6%。Microstructure and mechanical properties of hot deformed（as-forged,as-rolled）Ti-45 Al-7 Nb-0.3 W（atom fraction/%）alloy were investigated by optical microscope（OM）,scanning electron microscope（SEM）,transmission electron microscope（TEM）and tensile testing.Results show that the microstructure of as-cast Ti-45 Al-7 Nb-0.3 W alloy is near lamellar,which is mainly composed ofα2/γlamellar colonies with a mean size of about 100μm,and minorγas well asβphases located along the lamellar colonies boundaries.After hot canned forging,the lamellar colonies are broken and kinked.Compared with the as-cast alloy,the tensile strength of current as-forged alloy at room temperature increases by 77 MPa,and the tensile strength at 800℃increases by 36 MPa.After the subsequent hot-pack rolling,the microstructure of the as-forged alloy is transformed into fine duplex microstructure with an average grain size of 25μm,mechanical properties of current as-rolled alloy are further improved,the room temperature tensile strength increases to 603 MPa with the elongations of1.0%,the tensile strength at 800℃increases to 716 MPa with the elongation of 3.6%.

关 键 词：TIAL合金 包套锻造 包套轧制 组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]