组织结构对片层TiAl合金氧化行为影响  

Effects of Microstructure on Oxidation Behavior of Lamellar TiAl Alloys

作　　者：刘杰[1] 薛祥义[1] 杨劼人[1] 寇宏超[1] 李金山[1] 胡锐[1] 

机构地区：[1]西北工业大学凝尉技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2014年第12期3031-3036,共6页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划资助(2011CB605503)

摘　　要：以Ti-48Al-2Cr-2Nb(at%)合金为研究对象,通过热处理获得近片层和全片层两种显微组织,并在800℃空气条件下,进行了100 h的抗氧化性实验。利用OM、SEM、TEM、XRD和EDS对试样的微观结构、相组成及微区成分进行了分析。恒温氧化动力学结果表明:在800℃空气条件下,对于近片层和全片层两种Ti Al合金组织,其恒温氧化动力学曲线符合近抛物线规律,且近片层组织合金的抗氧化性能优于全片层组织。基于氧化动力学曲线、组织结构、氧化膜结构、氧化表面形貌分析,表明Ti Al合金的片层组织结构对其氧化行为具有不可忽视的影响。The oxidation behavior of Ti-48A1-2Cr-2Nb alloys with fully lamellar and nearly lamellar microstructure achieved by different heat treatments was investigated by a thermogravimetric method at 800 ℃ for 100 h. The morphology, phase composition and element distribution of the specimens were analyzed by OM, SEM, TEM, XRD and EDS. It is found that oxidation kinetic curves of the TiA1 alloys with nearly lamellar and fully lamellar microstructures accord with the parabolic curve law. And nearly lamellar microstructure has better oxidation resistance than fully lamellar microstructures, when the specimens are at 800 ℃ in air. Based on the analysis of oxidation kinetic, microstructure of substrate, microstructure of scale, surface morphology and phase of the sample, it is concluded that the microstructure of TiA1 alloy castings has a significant influence on the oxidation behavior.

关 键 词：TIAL合金 显微组织 片层结构 氧化行为 

分 类 号：TG146.23[一般工业技术—材料科学与工程]