Joining of C_f/SiBCN composite with two Ni-based brazing fillers and interfacial reactions

• 作 者: Wenwen Li Bo Chen Yi Xiong Huaping Xiong Yaoyong Cheng Wenjiang Zou
• 机 构: Welding and Plastic Forming Division, Beijing Institute of Aeronautical Materials,School of Material
• 出 处: Journal of Materials Science & Technology
• 发表日期: 2017年05期
• 关键词: filler ceramic joints joined distributing interfacial evident nitride amorphous

C_f/SiBCN ceramic composite was joined using Ni-19Cr-10Si(BNi5) and Ni-33Cr-24Pd-3.5Si-0.5B filler alloys at 1170 °C for 10 min. Two kinds of Ni-based filler alloys exhibited good wettability on the C_f/SiBCN composite, with a contact angle of 13° and 4°, respectively. The microstructures of the brazed joints were investigated by electron-probe microanalysis(EPMA), and three-point bend test was conducted for the joints at room temperature. When being brazed with BNi5 filler alloy, no evident reaction layer was observed at the surface of the joined composite, and the joint microstructure was characterized by Ni_2Si matrix with scatteringly distributing mixture compounds of Cr_(23)C_6, Ni_2Si and CrB. While Ni-Cr-Pd(Si,B)brazing alloy was used, a Cr_(23)C_6 reaction layer with a thickness of 11 μm was formed at the surface of the base composite. In the central part of the brazed joint, the phases were composed of Ni(Cr,Si) solid solution and complex compounds including Pd_2Si,(Ni,Pd)_2Si and Ni-B. The strength of C_f/SiBCN joint brazed with BNi5 filler alloy was 62.9 MPa at room temperature, whereas that with Ni-Cr-Pd(Si,B) filler alloy was at the same level.

C_f / SiBCN ceramic composite was joined using Ni-19Cr-10Si (BNi5) and Ni-33Cr-24Pd-3.5Si-0.5B filler alloys at 1170 ° C for 10 min. the C_f / SiBCN composite, with a contact angle of 13 ° and 4 °, respectively. The microstructures of the brazed joints were investigated by electron-probe microanalysis (EPMA), and three-point bend test was conducted for joints at room temperature . When being brazed with BNi5 filler alloy, no evident reaction layer was observed at the surface of the joined composite, and the joint microstructure was characterized by Ni_2Si matrix with scatteringly distributed mixture compounds of Cr_ (23) C_6, Ni_2Si and CrB. While Ni -Cr-Pd (Si, B) brazing alloy was used, a Cr_ (23) C_6 reaction layer with a thickness of 11 μm was formed at the surface of the base composite. In the central part of the brazed joint, the phases were composed of Ni (Cr, Si) solid solution and complex compounds including Pd_2Si, (Ni, Pd) _2Si and Ni-B. The strength of C_f / SiBCN joint brazed with BNi5 filler alloy was 62.9 MPa at room temperature, yet that with Ni-Cr-Pd (Si, B) filler alloy was at the same level.