Microstructure evolution and strengthening mechanism of Al2O3/Kovar joints brazed with TiB enhanced Ag-Cu-Ti based composite fillers

IF 3.8 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Vacuum Pub Date : 2025-03-15 DOI:10.1016/j.vacuum.2025.114241

Guo-Fu Ma , Xiao-Qiang Li , Qi Jiang , De-Zhi Zhu , Chao Yang

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引用次数: 0

Abstract

This paper achieved reliable joining of Al₂O₃ ceramics and Kovar alloys using Ag-Cu-Ti single filler and Ag-Cu-Ti + B composite filler. The synergistic effect of Ti and B on phase formation and the mechanical properties of the Al₂O₃/Kovar joints was systematically investigated. By optimizing the B content and brazing parameters, the typical interfacial structure of the joints obtained using Ag-Cu-6Ti+0.5B (wt.%) composite filler at 880 °C for 10 min was identified as Al₂O₃/Ti₃Cu₃O/Ag(s,s) + Cu(s,s) + TiCu + TiB/Fe₂Ti + Ni₃Ti/Ag(s,s) + Cu(s,s) + Fe₂Ti/Kovar. The results showed that B addition refines the joint microstructure by forming fine TiB whiskers and partially inhibits the dissolution and diffusion of alloying elements from the Kovar side. The joints brazed with the Ag-Cu-6Ti + 0.5B (wt.%) composite filler at 880 °C/10 min achieved a maximum shear strength of 131 MPa, representing a 37 % increase compared to the joints brazed with the Ag-Cu-6Ti (wt.%) single filler. The enhancement was attributed to the refinement of the joint microstructure and the alleviation of residual stresses. Additionally, the fracture analysis of the joints containing B revealed the dendritic Ag-Cu eutectic structure and extensive presence of the reactive layer Ti₃Cu₃O, offering new insights into the failure mechanism of brazed ceramic/metal joints.

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本文使用 Ag-Cu-Ti 单一填料和 Ag-Cu-Ti + B 复合填料实现了 Al2O3 陶瓷和 Kovar 合金的可靠连接。系统研究了 Ti 和 B 对 Al2O3/Kovar 接头的相形成和机械性能的协同效应。通过优化 B 含量和钎焊参数，确定了使用 Ag-Cu-6Ti+0.5B (wt.%) 复合填料在 880 °C 下 10 分钟获得的接头的典型界面结构为 Al2O3/Ti3Cu3O/Ag(s,s) + Cu(s,s) + TiCu + TiB/Fe2Ti + Ni3Ti/Ag(s,s) + Cu(s,s) + Fe2Ti/Kovar。结果表明，B 的加入通过形成细小的 TiB 晶须细化了接头的微观结构，并部分抑制了合金元素从 Kovar 侧的溶解和扩散。使用 Ag-Cu-6Ti + 0.5B (wt.%) 复合填料在 880 °C/10 分钟条件下钎焊的接头达到了 131 兆帕的最大剪切强度，与使用 Ag-Cu-6Ti (wt.%) 单一填料钎焊的接头相比提高了 37%。这一提高归功于接头微观结构的细化和残余应力的降低。此外，对含有 B 的接头进行的断裂分析显示了树枝状的 Ag-Cu 共晶结构和反应层 Ti3Cu3O 的广泛存在，为钎焊陶瓷/金属接头的失效机理提供了新的见解。

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

Vacuum 工程技术-材料科学：综合

CiteScore

6.80

自引率

17.50%

发文量

审稿时长

34 days

期刊介绍： Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences. A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below. The scope of the journal includes: 1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes). 2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis. 3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification. 4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.