SiC纤维增强TiAl基复合材料残余应力的调控  

Regulation of Residual Stress in SiC Fiber Reinforced TiAl Matrix Composites

作　　者：王敏涓 陈永刚 高帆 李虎 黄旭 黄浩 Wang Minjuan;Chen Yonggang;Gao Fan;Li Hu;Huang Xu;Huang Hao(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Key Laboratory of Advanced Titanium Alloys,Aero Engine Corporation of China,Beijing 100095,China;Techsim(Beijing)Technology Limited Company,Beijing 100085,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095 [2]中国航空发动机集团先进钛合金重点实验室,北京100095 [3]泰科信(北京)科技有限公司,北京100085

出　　处：《稀有金属》2023年第6期787-796,共10页Chinese Journal of Rare Metals

基　　金：国家科技重大专项(HT-J2019-VI-0007-0121)资助。

摘　　要：武器装备的轻量化设计以及更苛刻的高温服役要求,对材料提出了更高的要求。连续SiC纤维增强钛基复合材料(SiCf/Ti复合材料)具有良好的比强度和综合力学性能,成为了备受关注的轻质高温结构材料。但受局限于SiCf/TiAl复合材料的工艺特点,在成型过程中不可避免的会引入热残余应力而引起材料内部缺陷,对材料的力学性能带来不利影响。研究表明,SiCf/TiAl基体中具有较高的残余张应力,是SiCf/TiAl复合材料基体缺陷产生的主要原因。当SiC纤维体积分数(V_(f))为40.54%时,TiAl基体中最大残余张应力为1083.7 MPa(高于TiAl室温断裂强度)。为了调控SiCf/TiAl复合材料内部残余应力,采用有限元分析法计算了不同位置引入不同厚度的钛合金涂层,获得涂层的位置、厚度以及钛合金种类对SiCf/TiAl复合材料热残余应力的影响,从而获得SiCf/TiAl复合材料的残余应力的优化方案。对于SiC纤维V_(f)为40.54%的SiCf/TiAl复合材料而言,采用引入5μm(内)/1μm(外)涂层时,相比原始SiCf/TiAl复合材料,TiAl基体中最大残余张应力可降低约10%(低于TiAl室温断裂强度),从而在一定程度上降低复合材料中基体开裂等缺陷产生的风险。Continuous SiC fiber reinforced titanium matrix composites(SiC/Ti composites)were a kind of composites containing SiC fiber and titanium alloy,respectively as the reinforcement and the matrix.It could be widely used in the aerospace field due to its high specific strength,specific stifness and favorable fatigue resistance and creep resistance properties.The service temperature of Sic/Ti composites was closely related to the properties of the titanium alloy matrix.With the service temperature increasing,the titanium alloy matrix had been developed from medium-temperature titanium alloy gradually to high-temperature titanium alloy,and then to intermetallic compounds,such as Ti,AlNb and TiAl.The thermal residual stress would be induced by the mismatch of thermal expansion coefficient between titanium alloy and SiC fiber during the high temperature consolidation processing,which adversely affected the mechanical properties of the material.Therefore,it was important to control the residual stress of SiC/Ti composites.Although the measurement method and calculation of residual stress had been researched in the previous studies,definite scheme was still absent for the residual stress control.The finite element analysis(FEA)was applied to calculate the thermal residual stress of SiC/TiAl composites through establishing the hexagonal fiber arrangement model for exploring the stress optimization resource.Thus,the influence of coating position,thickness and type on the thermal residual stress of Sic/TiAl composites as well as the optimal scheme was obtained.Specifically,Workbench was used for finite element model building,in which the three-dimensional(3D)model including SiC fiber,C coating,TiAl matrix and the added inner and outer coatings.An 1/4 hexagonal model was used to calculate the residual stress.All of the displacements of the bottom node(x-z plane)in the y direction,the left side node(y-z plane)in the x direction and the top node(x-y plane)on the hexagon in the z direction were zero.In addition,the hypotenuse surf

关 键 词：连续SiC纤维增强钛基复合材料(SiCf/Ti复合材料) 有限元分析法(FEA) 残余应力 涂层位置 厚度 

分 类 号：TB333[一般工业技术—材料科学与工程]