Microstructural Evolution and Mechanical Properties of Wide Gap Brazing of K417G Superalloy [K417G高温合金大间隙钎焊的组织演变与性能研究]

作者：Cheng Z.; Li X.^*; Qu S.; Zhu D.; Li H.

来源：Rare Metal Materials and Engineering, 2021, 50(9): 3262-3269.

• Filler metal
• K417G superalloy
• Microstructure
• Tensile strength
• Wide gap brazing

Using mixture of low-melting nickel base alloy powder containing boron (LMP) and high-melting nickel base alloy powder (HMP) as the filler metal, K417G super alloy was brazedby wide gap brazing technology in a vacuum hot pressure sintering furnace. The effect of composition of filler metal on microstructure evolution and mechanical properties of joint was analyzed, and the strengthening mechanism of the joint was investigated. The results show that with the increase of the ratio of HMP in the filler metal, the content of borides in the joint decreases and the uniformity of the weld microstructure is improved. When the ratio of HMP in the filler metal increases to 95 wt%, B can be uniformly diffused into the HMP and the dispersed granular M3B2 borides at the interface areobtained. The tensile strength of the joint at room temperature and 600℃ is 971 and 934 MPa, respectively, reaching the strength of base metal. In addition, the fine particles of M23(C, B)6 carbon-boride are coherently precipitated in-situ in the joint and uniformly dispersed, and the coherent relationship of M23B2(C, B)6 and base metal is the key factor to realize the high quality wide gap brazing.

• 单位
  华南理工大学