电子束沉积TiAl合金的微观形貌及组织结构稳定性  

Micro-morphology and Microstructure Stability of TiAl Alloy Deposited by Electronic Beam

作　　者：马李[1,2] 何录菊[3] 邵先亦[4] 王古平[4] 张梦贤[4] 

机构地区：[1]广东石油化工学院机电工程学院,广东茂名525000 [2]哈尔滨工业大学复合材料与结构研究所,哈尔滨150001 [3]广东石油化工学院教育信息技术中心,广东茂名525000 [4]台州学院物理与电子工程学院,浙江台州318000

出　　处：《材料工程》2016年第1期89-95,共7页Journal of Materials Engineering

基　　金：广东石油化工学院人才引进项目(650119);广东省茂名市科技计划项目(915325);浙江省台州市科技计划项目(14GY02);浙江省科技厅公益性技术应用研究计划资助项目(2014C37085);国家自然科学基金资助项目(51404157)

摘　　要：利用大功率电子束物理气相沉积设备,采用单靶蒸镀方法制备厚度为0.3mm的自由态TiAl合金板,并对制备态样品进行不同温度（650-950℃）的真空退火处理。借助X射线衍射仪、扫描电子显微镜及透射电子显微镜分析退火处理对相组成及微观组织结构的影响。结果表明：Ti,Al元素饱和蒸气压的差异导致富Ti成分区和富Al成分区沿板材截面呈现交替变化,其组成相为α2-Ti3Al,γ-TiAl和τ-TiAl2;在650-950℃温度区间退火24h后,由于Al向Ti中扩散,呈现明显的界面融混和晶粒粗化,导致有序相含量的降低,其层状结构的退化受到孔洞形成、晶粒长大以及层间吞噬的影响。A free-standing TiAl based alloy thin sheet with thickness of 0.3mm was prepared by single source evaporation technology with high-power electron beam-physical vapour deposition（EB-PVD）system,and then the as-deposited samples were annealed in vacuum at 650-950℃.The effect of annealing on the microstructure and phase constitution of TiAl based alloy was studied with X-ray diffraction（XRD）,scanning electron microscope（SEM）and transmission electron microscope（TEM）.The results show that alternation of Ti-rich area and Al-rich area is presented along the cross section of the sheet due to deviation of saturated vapour pressure between Ti and Al element,and the as-deposited sample is composed ofα2-Ti3Al,γ-TiAl andτ-TiAl2 phases.After annealed at 650-950℃ for24 h,obvious interfacial reduction and grain coarsening appear with the diffusion of Al into Ti,leading to ordered phases reduce.The breakdown of layered structure is induced by pore formation,grain growth and grain boundary grooving.

关 键 词：电子束物理气相沉积 TIAL合金 饱和蒸气压 微观形貌 结构稳定性 

分 类 号：TG146[一般工业技术—材料科学与工程]