Effect of filler metal on the microstructural evolution and mechanical properties of wide gap brazed K417G superalloy joints

Li, Xiaoqiang; Zhang, Cheng; Qu, Shenguan; Zhu, Daoben; Li, Huiyun

doi:10.1016/j.vacuum.2020.109967

Cited by 6 publications

(1 citation statement)

References 37 publications

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“…In the ISZ-1 of the HT2 joint, the morphology and size of the γ and S-γ' phases have no obvious change compared with that of the HT1 joint, but needle boride precipitates in In the NSZ of the HT1 joint, a large number of dense large skeleton borides are distributed, these borides have the characteristics of a hard and brittle structure, which leads to high slight hardness in NSZ. Researchers [35] have reported that the presence of boride in the joints leads to a significant increase in microhardness in this area. In HT2 joints, the microhardness of NSZ can be found to be decreased.…”

Section: Microhardnessmentioning

confidence: 99%

Effects of Post-Weld Heat Treatment on Microstructure and Mechanical Properties of the Brazed Joint of a Novel Fourth-Generation Nickel-Based Single Crystal Superalloy

et al. 2023

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A novel fourth-generation nickel-based single crystal superalloy was brazed with Co-based filler alloy. The effects of post-weld heat treatment (PWHT) on the microstructure and mechanical properties of brazed joints were investigated. The experimental and CALPHAD simulation results show that the non-isothermal solidification zone was composed of M3B2, MB-type boride and MC carbide, and the isothermal solidification zone was composed of γ and γ’ phases. After the PWHT, the distribution of borides and the morphology of the γ’ phase were changed. The change of the γ’ phase was mainly attributed to the effect of borides on the diffusion behavior of Al and Ta atoms. In the process of PWHT, stress concentration leads to the nucleation and growth of grains during recrystallization, thus forming high angle grain boundaries in the joint. The microhardness was slightly increased compared to the joint before PWHT. The relationship between microstructure and microhardness during the PWHT of the joint was discussed. In addition, the tensile strength and stress fracture life of the joints were significantly increased after the PWHT. The reasons for the improved mechanical properties of the joints were analyzed and the fracture mechanism of the joints was elucidated. These research results can provide important guidance for the brazing work of fourth-generation nickel-based single crystal superalloy.

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Section: Microhardnessmentioning

confidence: 99%