Microstructural evolution and mechanical property of a SiCf/SiC composite/Ni-based superalloy joint brazed with an Au-Cu-Ti filler

作者：Yang, Jia; Zhang, Xunye; Ma, Guanglu; Lin, Panpan^*; Xu, Yanqiang; Lin, Tiesong^*; He, Peng^*; Long, Weimin; Li, Jian

来源：Journal of the European Ceramic Society, 2021, 41(4): 2312-2322.

DOI：10.1016/j.jeurceramsoc.2020.08.065

• SiCf/SiC composite
• Ni-based superalloy
• Au-Cu-Ti filler
• Microstructure
• Mechanical properties

A new Au-Cu-Ti filler featuring superior mechanical properties was developed to enable the brazing of a SiCf/SiC composite (CMCs) to itself and a Ni-based superalloy (GH536). The progression of the interfacial reactions was studied using a combination of thermodynamic calculations and experimental observations. It was found that the interfacial reaction was Ti-dominant at the early brazing stage and then gradually transformed to Ni-dominant with the continuous dissolution of the GH536 substrate. Thus, the typical microstructure of GH536/Ti-Ni-Cr-Fe+ (Au, Cu)ss + MoNiSi/Ni-Cr-Fe-Si-C (Ni2Si + Fe2Si + Cr3C2)+(Au, Cu)ss/Ni2Si + TiC+(Au, Cu)ss/ Cr3C2+Ni2Si + TiC + Fe2Si/CMCs could be described by the following three stages: a Ti-dominated stage, full interdiffusion stage, and Ni-dominated stage. A maximum shear strength of 36 MPa was obtained for joints brazed at 1050 degrees C for 10 min, at which a failure occurred at the CMCs/brazing seam interface. The control of the interfacial reactions and the stress relaxation of (Au, Cu)ss contributed to the superior mechanical performance of the composite.

• 单位
  harbin inst technol; 郑州机械研究所