The paper aims at understanding the microstructure evolution of the diffusion brazing of γ-TiAl intermetallic compound using two Ni-based filler metals, a ternary Ni-Si-B, and a quinary Ni-Cr-Fe-Si-B. It was found that the joint region comprised of two distinct zones: analogous reaction layers adjacent to the TiAl substrates and a solidified zone at the middle of the joint region. The reaction layers consisted of separate intermetallic phases regions including ternary and binary Ti-Ni-Al intermetallic compounds. The solidified zone mainly composed of the Al1-xNi3Six isostructural solid solution and athermally Ni-boride or Ni-Cr rich borides containing eutectic microstructures at the joint centerline. The maximum shear strength was 240 MPa, and obtained by using Ni-Cr-Fe-Si-B filler metal. Fracture of the joint with Ni-Cr-Fe-Si-B filler occurred in the reaction layer/solidified zone interface, but joint with Ni-Si-B filler was fractured at solidified zone. GRAPHICAL ABSTRACT

中文翻译：

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γ-TiAl金属间化合物使用非晶Ni基填充金属扩散钎焊过程中的相变研究

本文旨在了解使用两种 Ni 基填充金属、三元 Ni-Si-B 和五元 Ni-Cr-Fe-Si-B 扩散钎焊 γ-TiAl 金属间化合物的微观结构演变。发现连接区由两个不同的区域组成：与 TiAl 基底相邻的类似反应层和位于连接区中间的凝固区。反应层由单独的金属间相区域组成，包括三元和二元 Ti-Ni-Al 金属间化合物。凝固区主要由 Al1-xNi3Six 等结构固溶体和在接头中心线处含有共晶组织的无热镍硼化物或富镍铬硼化物组成。最大剪切强度为 240 MPa，使用 Ni-Cr-Fe-Si-B 填充金属获得。Ni-Cr-Fe-Si-B填料接头断裂发生在反应层/凝固区界面，而Ni-Si-B填料接头在凝固区断裂。图形概要