热压工艺对SiC_(f)/Ti复合材料界面反应层生长影响的数值模拟  

Numerical simulation of effect of hot-pressing process on growth of interfacial reaction layer in SiC_(f)/Ti composites

作　　者：唐洪武 张晓敏[1,2] 赵志鹏 张恒嘉 Tang Hongwu;Zhang Xiaomin;Zhao Zhipeng;Zhang Hengjia(College of Aerospace Engineering,Chongqing University,Chongqing 400044,China;Chongqing Key Laboratory of Mechanics of Heterogeneous Material Mechanics,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学航空航天学院,重庆400044 [2]重庆大学非均质材料力学重庆市重点实验室,重庆400044

出　　处：《金属热处理》2023年第2期232-241,共10页Heat Treatment of Metals

基　　金：国家自然科学基金面上项目(11872130);重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0084)。

摘　　要：提出一个热-力-扩散-反应强耦合相场模型来研究热压烧结制备工艺对连续碳化硅纤维增强钛基复合材料中金属间化合物生长规律的影响。模拟结果表明,在两种不同温度下各个界面反应层(Ti_(3)SiC_(2)/Ti_(5)Si_(3)Cx/Ti_(5)Si_(3)Cx+TiC/TiC)的厚度生长与试验值吻合较好。增大外加压力能促进界面层厚度的生长,但对其中抗拉强度最低的Ti_(5)Si_(3)层的生长起显著的抑制作用,同时使各界面反应层由周向拉应力状态逐渐转变为压应力。温度的升高使断裂韧度最大的Ti_(3)SiC_(2)层厚度增大,但也使总界面层和Ti_(5)Si_(3)层的厚度增加。因此,在制备工艺上适当增加压力并选择合适的温度,得到厚度适宜的界面反应层的同时,尽可能使Ti_(5)Si_(3)层变薄和Ti_(3)SiC_(2)层变厚是提高SiCf/Ti复合材料力学性能的重要途径。A phase field model based on strongly coupled thermo-mechano-diffusion-reactional theory was proposed to study the effect of hot-pressing sintering fabrication process on growth law of intermetallic compounds in the continuous silicon carbide fiber reinforced titanium matrix composites. The simulation results show that the thickness of each interface reaction layer is consistent with the experiment at two different temperatures. Further research shows that the applied load can promote the growth of interface reaction layer, but the growth of Ti_(5)Si_(3) layer is significantly inhibited, which has the lowest tensile strength. With the increase of applied load, the circumferential stress changes from tension to compression. The thickness of Ti_(3)SiC_(2)layer increases with temperature rising, which has the maximum fracture toughness, as well as the thickness of the total interface reaction layer and Ti_(5)Si_(3) layer are also increased. Therefore, it is an important way to improve the mechanical properties of SiCf/Ti composites by properly increasing the pressure and selecting the appropriate temperature in the preparation process to obtain the interface reaction layer with the appropriate thickness, meanwhile, making the Ti5Si3layer thinner and the Ti_(3)SiC_(2) layer thicker as far as possible.

关 键 词：SIC纤维增强钛基复合材料 热-力-扩散-反应耦合 相场法 界面层生长 热压烧结 

分 类 号：TB333[一般工业技术—材料科学与工程]