Y对粉末冶金无压烧结Ti-22Al-25Nb合金组织与力学性能的影响  

Effect of Y on microstructure and mechanical properties of Ti-22Al-25Nb alloys prepared by powder metallurgic pressureless sintering

作　　者：张亚然 李彦默 秦豪杰 蔡奇 刘永长[4] ZHANG Ya-ran;LI Yan-mo;QIN Hao-jie;CAI Qi;LIU Yong-chang(Material Science Research Center,Xingtai University,Xingtai 054001,China;Luoyang Ship Materials Research Institute,Luoyang 471000,China;School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China)

机构地区：[1]邢台学院材料科学研究中心,河北邢台054001 [2]中国船舶集团第七二五研究所,河南洛阳471000 [3]北京理工大学材料学院,北京100081 [4]天津大学材料科学与工程学院,天津300354

出　　处：《材料热处理学报》2023年第11期83-91,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金青年项目(52104389);国家自然科学基金面上项目(52171027);河北省高等学校青年拔尖人才计划(BJK2023008);邢台市重点研发计划项目(2021ZC017);北京理工大学学术启动计划(202008002)。

摘　　要：采用“冷等静压+无压烧结”工艺制备了不同Y含量的Ti-22Al-(25-x)Nb-xY(x=0、0.5、1.0、1.5、2.0 at%)合金,研究了Y元素含量对合金微观组织、压缩力学性能和烧结过程的影响。结果表明:未添加Y的合金的组织为等轴α_(2)相和B2+O的魏氏组织;Y元素会抑制Ti与Al之间的反应,并生成Y_(2)O_(3)相;Y元素的加入会抑制晶界α_(2)相的形成,并使等轴α_(2)相的尺寸细化,且数量也减少;随着Y元素含量的增加,合金的强度先降低后升高,塑性先升高后降低。Y添加量为1.5 at%时合金的塑性最佳,α_(2)相的含量和形貌是影响合金性能的主要因素。未添加Y的合金烧结过程中经历的相变为Ti+Al→TiAl_(3)→TiAl→Ti3Al,而添加Y的合金烧结过程还存在Ti+YAl_(3)→TiAl_(3)+Y和4Y+3O2→2Y_(2)O_(3)的反应。Ti-22Al-(25-x)Nb-xY(x=0,0.5,1.0,1.5 and 2.0 at%)alloys with different Y contents were prepared by cold isostatic pressing and pressureless sintering method.The effects of Y element content on microstructure,compressive mechanical properties and sintering process of the alloys were studied.The results indicate that the microstructure of the alloy without Y addition is equiaxedα_(2)phase and B2+O Widmanstätten structure.Y element will inhibit the reaction between Ti and Al and generate Y_(2)O_(3)phase.The addition of Y element will suppress grain boundariesα_(2)phase formation and the size of the equiaxedα_(2)phase is refined and the number is also reduced.As the content of Y element increases,the strength of the alloy first decreases and then increases,and the plasticity first increases and then decreases.The alloy exhibits the best plasticity when the Y addition is 1.5 at%,the content and morphology of theα_(2)phase are the main factors affecting the properties of the alloy.The phase transition experienced during the sintering process of the alloy without Y addition is Ti+Al→TiAl_(3)→TiAl→Ti3Al,while the sintering process of the alloy with Y addition also involves reactions of Ti+YAl_(3)→TiAl_(3)+Y and 4Y+3O_(2)→2Y_(2)O_(3).

关 键 词：Ti_(2)AlNb基合金 粉末冶金 微观组织 力学性能 烧结过程 

分 类 号：TG146.2[一般工业技术—材料科学与工程]