Ni71CrSi中间层钎焊连接C/C复合材料与镍基高温合金GH3044

Brazing of C/C Composites and GH3044 Ni-Based Superalloy Using Ni71CrSi as the Interlayer

以Ni71CrSi为中间层在1 180℃×30 min的钎焊条件下,对C/C复合材料和镍基高温合金进行钎焊试验。研究了Ni71CrSi对C/C复合材料和表面SiC改性的C/C复合材料的润湿性。利用扫描电子显微镜、能谱分析仪、万能试验机和微米压痕仪分别对接头的界面组织、显微硬度和剪切断裂过程进行了研究。结果表明,表面未改性的C/C复合材料在连接过程中直接失效,而表面SiC改性的C/C复合材料与镍基合金的接头连接良好,且接头剪切强度达到35.08 MPa,断裂方式呈假塑性断裂。机理分析表明,镍基钎料较好地润湿表面SiC改性的C/C复合材料,接头的显微硬度分布呈中间高两边低的变化趋势,且形成了表面改性C/C/Ni(s.s)+Cr7C3+Ni3Si/Ni(s.s)+Cr3C2+Ni3Si/Ni(s.s)+Cr3C2+MC+Ni3Si/Ni3Si+MC+Ni(s.s)/GH3044界面结构。

C/C composites and Nickle-based superalloy GH3044 were brazed at 1 180 ℃ for 30 rain using the Ni71CrSi filler as interlayer. The wettability of filler on the surface of C/C composites and SiC modified C/C composites was stud- ied. The mierostructure, microhardness and shear fi＇acture of the joint between C/C composites and GH3044 were investi- gated by scanning electron microscopy, energy-dispersive spectrometry, material universal testing machine and Micro-in- dentation instrument, respectively. Results showed that the joint without SiC coating got failed during the brazing process. Ni71 CrSi can well braze Niekle-based superalloy and C/C composites with SiC coating. The shear strength of joint with SiC coating at room temperature was up to 35, 08 MPa. The joint exhibited pseudo-plastic fracture behavior. Mechanism analy- sis indicated that this filler could wet modified C/C composites well. The hardness distribution of the joint presented a trend with high value at the middle and low value at the both sides, and the interracial structure of joints was： C/C com- posites with SiC coatingv/Ni（ s. s） ＋ CrTC3 ＋ Ni3Si/Ni（ s, s） ＋ Cr3C2 ＋ Ni3Si/Ni（ s. s） ＋ Cr3C2 ＋ MC ＋ Ni3Si/Ni3Si ＋ MC ＋ Ni（ s. s）/GH3044.