基于Si-CaO/Al_(2)O_(3)-Si三明治结构的碳/碳复合材料高强度扩散连接  

High-strength Diffusion Bonding of Carbon/Carbon Composites Based onSi-CaO/Al_(2)O_(3)-Si Sandwich Structure

作　　者：王晓昱 贾建刚[1,2] 刘第强 巨佳康 柴昌盛 季根顺[1] WANG Xiaoyu;JIA Jiangang;LIU Diqiang;JU Jiakang;CHAI Changsheng;JI Genshun(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Science and Technology on Wear and Protection of Materials,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Gansu Haoshi Carbon Fiber Co.,Ltd.,Lanzhou 730000,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学材料科学与工程学院,兰州730050 [3]中国科学院兰州化学物理研究所材料磨损与防护重点实验室,兰州730000 [4]甘肃郝氏炭纤维有限公司,兰州730000

出　　处：《材料导报》2022年第13期73-78,共6页Materials Reports

基　　金：甘肃省科技重大专项(1602GKDD012);白银市急需紧缺人才引进重点项目(第二批)。

摘　　要：通过在碳/碳(简称C/C)复合材料表面依次铺设Si、CaO/Al_(2)O_(3)微晶玻璃(简称CA)和Si浆料,形成一种三明治结构的涂层,经热压扩散连接实现C/C复合材料自身连接。C/C复合材料和玻璃陶瓷之间的润湿性差,而Si与C具有良好的亲和性,因此希望通过Si和基体C在高温下原位生成SiC,同时Si和CA接触扩散并进行化学反应形成硅酸盐玻璃,使得采用微晶玻璃来连接C/C复合材料成为可能。对接头的微观组织结构和力学性能进行了研究,结果表明:随着保温时间延长,接头连接层上的裂纹和孔洞减少,连接层变得更为致密。在1480℃、0.5~1 MPa及保温90 min的工艺条件下,所得接头在室温下的剪切强度达30.45 MPa。熔融的中间层产物与C/C复合材料具有较好的浸润性,并渗透填充到C/C复合材料基体的空隙中形成了“钉扎结构”,从而提高了接头的剪切强度。Asandwich structure layer is formed by sequentially laying Si,CaO/Al_(2)O_(3)glass-ceramics(referred to as CA)and Si slurry coatings on the surface of the carbon/carbon(referred to as C/C)composites.Joining of the C/C composites to itself is realized by hot press diffusion bonding.The wettability between C/C composites and glass-ceramics is poor,whereas Si and C have a good affinity.It is thus expected that SiC is generated through in-situ reaction between Si and C matrix under high temperature,while Si and CA undergo mutual diffusion and chemical reaction to form silicate glass.By this means,glass-ceramics can be used to join C/C composites.The microstructure and mechanical properties of the joints were studied.Results show that the cracks and holes on the joint connecting layer are reduced and the connecting layer becomes denser with the extension of the heat preservation time.Under the conditions of 1480℃,0.5—1 MPa and holding time of 90 min,the shear strength of the resulting joint at room temperature reaches 30.45 MPa.The molten interlayer product has good wettability with the C/C composites,and penetrates the voids of the C/C composites matrix to form a‘pinning structure’,thereby improving the shear strength of the joints.

关 键 词：碳/碳复合材料 CaO/Al_(2)O_(3)微晶玻璃 扩散连接 组织结构 剪切强度 

分 类 号：TB332[一般工业技术—材料科学与工程]