【作者】 李树杰； 卢越焜； 刘洪丽； 毛样武； 陈志军；

【Author】 Li Shujie~1,Lu Yuekun~1,Liu Hongli~1,Mao Yangwu~1,Chen Zhijun~2 (1 School of Materials Science and Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100083; 2 The 46th Research Institute,Shaanxi Huaxing Aircraft Wheel and Brake System Co.Ltd.,Xingping,Shaanxi 713106)

【机构】 北京航空航天大学材料科学与工程学院； 陕西华兴航空机轮刹车系统有限责任公司第46研究所；

【摘要】 采用陶瓷先驱体聚合物聚碳硅烷(PCS)与活性填料Al-Si粉作为焊料,通过反应成形连接工艺成功地连接了碳纤维增强碳化硅复合材料(C/SiC)。在连接温度为1000～1300℃的试验范围内,当连接温度为1150℃时,接头剪切强度达到最高值45.1 MPa,断裂部位部分位于焊料反应产物层内部,部分位于邻近连接界面的C/SiC母材内部,为混合断口。这种断口表明连接材料与母材有很好的润湿性和很强的界面结合力。微观结构及成分分析显示,焊料反应产物层结构较为均匀致密,且与母材间界面结合良好。活性填料Al-Si粉在连接过程中参与化学反应,促进界面结合,使连接强度提高。但是,焊料反应产物层的结晶程度过高有损于连接强度。更多还原

【Abstract】 Carbon fiber reinforced SiC composite(C_f/SiC) has been successfully joined by reaction joining process using polycarbosilane(PCS) with active additives Al- Si powders as joining material.Samples were joined at temperatures ranging from 1000～1300℃.The maximum shearing strength of joints is obtained at 1150℃,which is 45.1 MPa.The fracture surface of these joints is partially located inside the interlayer,which is formed from the joining material in joining process, and partially inside the welding base material C_f/SiC close to the interface between the C_f/SiC and the interlayer.This kind of fracture surface is called as the mixed-mode fracture,which indicates a good wettability of the system and a sound bonding between the interlayer and the welding base material. The microstructure and composition of the weld zone were analyzed.The results show that the interlayer is densified,and the contact at the interfaces is good.The active additives Al-Si powders participate in the chemical reactions in joining process,which contribute to the interfacial bonding, resulting in the increasing of weld strength.But excessive crystallization of the interlayer is harmful to the weld strength.更多还原