Microstructure, shear strength and failure mechanism of TZM/graphite joints bonded by a SPS pressureless brazing technique

IF 5.5 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization Pub Date : 2025-09-01 DOI:10.1016/j.matchar.2025.115520

Binrong Nong , Zhiqiang Fan , Jiuxing Zhang , Cuiliu Han , Jingwen Zhang , Donghui Li , Yan Wang

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引用次数: 0

Abstract

This study developed a spark plasma sintering (SPS) pressureless brazing technique to join TZM alloy and graphite, using a self-designed mold with Ti foil as the interlayer. The effect of brazing temperature on the microstructure and shear strength of the TZM/graphite joints as well as the interfacial failure mechanism were investigated. At the optimal brazing temperature of 1580 °C, the joint interface exhibited no detectable defects such as cracks or un-welded regions, with the microstructure consisted of island-like TiC, plate-like TiC, finger-like TiC coexisted with (βTi, Mo) solid solution, and continuous (βTi, Mo) solid solution. The shear strength of TZM/graphite joint brazed at 1580 °C reached a maximum of 55.34 MPa, with fracture predominantly occurred at the bonding interface between graphite and plate-like TiC. The island-like TiC, formed by the reaction of the partially melted Ti diffusing into graphite pores, promoted crack deflection or even crack arrest, thereby enhancing the interfacial strength. Fracture analysis revealed a mixture of intergranular fracture along the granular TiC and transgranular cleavage fracture within island-like TiC. This study demonstrates the feasibility of SPS pressureless brazing for fabricating high-strength TZM/graphite joint with favourable microstructural characteristics.

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SPS无压钎焊TZM/石墨接头的显微组织、抗剪强度及破坏机理

本研究采用自行设计的模具，以钛箔为中间层，采用火花等离子烧结（SPS）无压钎焊技术连接TZM合金和石墨。研究了钎焊温度对TZM/石墨接头组织和抗剪强度的影响以及界面破坏机制。在最佳钎焊温度为1580℃时，接头界面未出现裂纹和未焊区等缺陷，显微组织为岛状TiC、板状TiC、指状TiC与（βTi, Mo）固溶体共存以及连续（βTi, Mo）固溶体。1580℃时钎焊的TZM/石墨接头抗剪强度最大，达到55.34 MPa，断裂主要发生在石墨与片状TiC的结合界面。部分熔化的Ti扩散到石墨孔中反应形成岛状TiC，促进裂纹偏转甚至裂纹止裂，从而提高界面强度。断口分析显示沿颗粒状TiC的沿晶断裂和岛状TiC的沿晶解理断裂混合。本研究证明了SPS无压钎焊制备具有良好显微组织特性的高强度TZM/石墨接头的可行性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Materials Characterization 工程技术-材料科学：表征与测试

CiteScore

7.60

自引率

8.50%

发文量

746

审稿时长

36 days

期刊介绍： Materials Characterization features original articles and state-of-the-art reviews on theoretical and practical aspects of the structure and behaviour of materials. The Journal focuses on all characterization techniques, including all forms of microscopy (light, electron, acoustic, etc.,) and analysis (especially microanalysis and surface analytical techniques). Developments in both this wide range of techniques and their application to the quantification of the microstructure of materials are essential facets of the Journal. The Journal provides the Materials Scientist/Engineer with up-to-date information on many types of materials with an underlying theme of explaining the behavior of materials using novel approaches. Materials covered by the journal include: Metals & Alloys Ceramics Nanomaterials Biomedical materials Optical materials Composites Natural Materials.