Microstructure and Mechanical Properties of W/Cu Joints Brazed with CuMn-based Filler Metal

LU Haotian; LI Shishuo; QU Yuanhao; SHENG Lanbing; ZHANG Xiaohang; SHEN Yu

doi:10.3969/j.issn.1674-6457.2026.08.008

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Journal of Netshape Forming Engineering ›› 2026, Vol. 18 ›› Issue (8) : 89-98. DOI: 10.3969/j.issn.1674-6457.2026.08.008

Key Technologies for Precision Forming of High-end Energy and Aerospace Equipment Components

Microstructure and Mechanical Properties of W/Cu Joints Brazed with CuMn-based Filler Metal

LU Haotian^*, LI Shishuo, QU Yuanhao, SHENG Lanbing, ZHANG Xiaohang, SHEN Yu

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Abstract

The work aims to address the joining difficulties caused by metallurgical incompatibility and large mismatch in coefficient of thermal expansion between W and Cu by designing and preparing two high-manganese filler metals (Cu-23.5Mn- 9Ni and Cu-23.5Mn-11Co) and systematically investigating the effects of Ni and Co on the microstructure, interfacial reaction behavior and mechanical properties of brazed joints. W/Cu joints were fabricated by vacuum brazing. The microstructure, elemental distribution and shear fracture morphology of the brazed seams were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Room-temperature shear strength of the joints was measured with a universal electronic testing machine to evaluate the mechanical properties under different filler metals and process conditions. Under the brazing condition of 900 ℃ and a holding time of 10 min, both filler metals achieved reliable metallurgical bonding between W and Cu, resulting in dense brazed seams without continuous brittle phases. For the CuMnNi filler, Ni was mainly enriched at the W/filler interface, and the joint exhibited an average shear strength of (163.1±10.2) MPa. For the CuMnCo filler, Co diffused into the W substrate by forming a solid solution, creating a compositionally graded transition layer that enhanced interfacial bonding strength, and the joint achieved an average shear strength of (182.6±9.6) MPa. The shear fractures of both joints exhibited a mixed ductile-brittle failure mode, with morphologies comprising dimples, tearing ridges and local cleavage facets. The solid-solution diffusion of Co into the W substrate significantly enhances the interfacial bonding strength of the CuMnCo brazed joint, rendering its comprehensive mechanical performance superior to that of the CuMnNi counterpart. This work provides a technical reference for future research and applications of W/Cu brazing.

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W/Cu joining / CuMn-based filler metal / vacuum brazing / solid solution strengthening / shear strength

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LU Haotian, LI Shishuo, QU Yuanhao, SHENG Lanbing, ZHANG Xiaohang, SHEN Yu. Microstructure and Mechanical Properties of W/Cu Joints Brazed with CuMn-based Filler Metal[J]. Journal of Netshape Forming Engineering. 2026, 18(8): 89-98 https://doi.org/10.3969/j.issn.1674-6457.2026.08.008

References

[1] HIRAI T, BARABASH V, ESCOURBIAC F, et al.ITER Divertor Materials and Manufacturing Challenges[J]. Fusion Engineering and Design, 2017, 125: 250-255.
[2] 彭吴擎亮, 李强, 常永勤, 等. 核聚变堆偏滤器热沉材料研究现状及展望[J]. 金属学报, 2021, 57(7): 831-844.
PENG W, LI Q, CHANG Y Q, et al.A Review on the Development of the Heat Sink of the Fusion Reactor Divertor[J]. Acta Metallurgica Sinica, 2021, 57(7): 831-844.
[3] KRAUSS W, LORENZ J, KONYS J, et al.Mechanical Characterization of Electrochemically Based W-Cu Joints for Low-Temperature Heat Sink Application[J]. Fusion Engineering and Design, 2017, 124: 220-225.
[4] 范景莲, 杨树忠, 刘涛, 等. W-Cu复合材料与Cu的扩散连接工艺[J]. 粉末冶金材料科学与工程, 2015, 20(2): 182-186.
FAN J L, YANG S Z, LIU T, et al.Diffusion Bonding Process between W-Cu Composite and Cu[J]. Materials Science and Engineering of Powder Metallurgy, 2015, 20(2): 182-186.
[5] ZOU Y Q, KANG L, YU J B, et al.Experiments and Analysis of Thin Tungsten Slice and W/Cu Brazing for Primary Collimator Scraper in CSNS/RCS[J]. Science China Physics, Mechanics and Astronomy, 2014, 57(4): 680-683.
[6] 刘国化, 魏明霞, 高勤琴, 等. AgCuTi活性钎料的研究进展[J]. 贵金属, 2020, 41(S1): 27-33.
LIU G H, WEI M X, GAO Q Q, et al.Research Progress of AgCuTi Active Solder[J]. Precious Metals, 2020, 41(S1): 27-33.
[7] YAO W, ZHONG B, ZHANG Y M, et al.Effects of Brazing Parameters on Interfacial Reaction Layer Characteristics and Mechanical Performance of Brazed Cu/Si₃N₄ Using Ag-Cu-Ti Filler Alloy[J]. Materials Science and Engineering: A, 2025, 936: 148400.
[8] LIU Y Q, ZHANG Y, YU C, et al.Double Seam Welding of 304 Stainless Steel with Al₂O₃ Ceramics Using AgCuInTi Reactive Fillers[J]. Optics & Laser Technology, 2025, 189: 113043.
[9] 房永强, 余泽利, 张曙香, 等. 核级银铟镉合金稳态蠕变速率测量不确定度评定[J]. 塑性工程学报, 2023, 30(9): 211-216.
FANG Y Q, YU Z L, ZHANG S X, et al.Evaluation of Uncertainty in Steady Creep Rate Measurement of Nuclear Grade Ag-in-Cd Alloy[J]. Journal of Plasticity Engineering, 2023, 30(9): 211-216.
[10] 陈远亭, 李先芬, 陈柏炎. 钨的钎焊研究进展[J]. 有色金属材料与工程, 2018, 39(6): 32-36.
CHEN Y T, LI X F, CHEN B Y.Research Progress in Brazing of Tungsten[J]. Nonferrous Metal Materials and Engineering, 2018, 39(6): 32-36.
[11] PINTSUK G, BRÜNINGS S E, DÖRING J E, et al. Development of W/Cu-Functionally Graded Materials[J]. Fusion Engineering and Design, 2003, 66/67/68: 237-240.
[12] 杨骄, 龙伟民, 鲍丽, 等. 铜基钎料的研究进展及应用[J]. 电焊机, 2022, 52(4): 21-28.
YANG J, LONG W M, BAO L, et al.Research Progress and Application of Copper-Based Brazing Filler Metal[J]. Electric Welding Machine, 2022, 52(4): 21-28.
[13] LIU X, LIAN Y Y, CHEN L, et al.Tungsten Joining with Copper Alloy and Its High Heat Load Performance[J]. Journal of Nuclear Materials, 2014, 455(1/2/3): 382-386.
[14] DE PRADO J, SÁNCHEZ M, UREÑA A. Wettability Study of a Cu-Ti Alloy on Tungsten and EUROFER Substrates for Brazing Components of DEMO Fusion Reactor[J]. Materials & Design, 2016, 99: 93-101.
[15] 刘仕福. 钨与铜合金的TLP连接及石墨表面金属化研究[D]. 南京: 南京航空航天大学, 2006: 30-31.
LIU S F.Study on TLP Connection between Tungsten and Copper Alloy and Metallization of Graphite Surface[D]. Nanjing: Nanjing University of Aeronautics and Astronautics, 2006: 30-31.
[16] MAKSIMOVA S V, KHORUNOV D V F, BARABASH V R. Problems in Fabricating Sections of a Divertor of a Thermonuclear Synthesis Reactor by Brazing[J]. Welding International, 1995, 9(1): 47-50.
[17] SINGH K P, KHIRWADKAR S S, BHOPE K, et al.Feasibility Study on Joining of Multi-Layered W/Cu-CuCrZr-SS316L-SS316L Materials Using Vacuum Brazing[J]. Fusion Engineering and Design, 2018, 127: 73-82.
[18] KHIRWADKAR S S, SINGH K P, Y PATIL, et al. Fabrication and Characterization of Tungsten and Graphite Based PFC for Divertor Target Elements of ITER Like Tokamak Application[J]. Fusion Engineering and Design, 2011, 86(9/10/11): 1736-1740.
[19] ZHAO S X, ZHANG Y, ZHANG T X, et al.Fabrication of a W/Cu/Steel Mock-up via Optimizing the Brazing Parameters[J]. Fusion Engineering and Design, 2023, 195: 113941.
[20] TAO Z H, LIU H D, ZHAO S X, et al.Deuterium Permeation and Retention Behavior in Copper-Based Brazing Filler Materials[J]. Nuclear Materials and Energy, 2024, 40: 101694.
[21] 刘佳惠. YG6C硬质合金与42CrMo钢真空钎焊及热处理一体化工艺研究[D]. 镇江: 江苏科技大学, 2011: 32-33.
LIU J H.Study on Vacuum Brazing and Heat Treatment Integration Process of YG6C Cemented Carbide and 42CrMo Steel[D]. Zhenjiang: Jiangsu University of Science and Technology, 2011: 32-33.
[22] 朱蕾蕾, 王海龙. 基于CuMnCo钎料的YG6C硬质合金与16Mn钢的真空钎焊工艺研究[J]. 热加工工艺, 2012, 41(13): 185-187.
ZHU L L, WANG H L.Study on Vacuum Brazing of YG6C Cemented Carbide and 16Mn Steel with CuMnCo Filler Mental[J]. Hot Working Technology, 2012, 41(13): 185-187.
[23] MAKSYMOVA S V, KOVALCHUK P V, et al.The Influence of Iron on the Structure and Technological Characteristics of Cu-Mn-Co Brazing Filler Metal[J]. The Paton Welding Journal, 2023(8): 36-43.
[24] ZHANG P F, HE H J, ZHANG Z S, et al.New Characteristics and Bonding Mechanisms of the Directly Bonded W/Cu Plates[J]. JOM, 2025, 77(6): 4493-4506.
[25] CHEN L, LIAN Y Y, LIU X.Behavior of Brazed W/Cu Mockup under High Heat Flux Loads[J]. Plasma Science and Technology, 2014, 16(3): 278-282.
[26] 黎志勇. 拉拔形变率对Al₂O₃颗粒增强Cu基复合材料组织和硬度的影响[J]. 粉末冶金工业, 2018, 28(5): 55-58.
LI Z Y.Effect of Drawing Deformation Rate on Microstructure and Hardness of Al₂O₃ Particle Reinforced Cu Matrix Composites[J]. Powder Metallurgy Industry, 2018, 28(5): 55-58.
[27] SCHINDZIELORZ N, NOWAK K, MAISEL S B, et al.Phase Behavior and Mechanical Properties of Ni-W Studied by First-Principles Calculations and Ab Initio Based Thermodynamics[J]. Acta Materialia, 2014, 75: 307-315.
[28] PETISME M V G, JOHANSSON S A E, WAHNSTRÖM G. A Computational Study of Interfaces in WC-Co Cemented Carbides[J]. Modelling and Simulation in Materials Science and Engineering, 2015, 23(4): 045001.
[29] 李凤, 唐会毅, 吴保安, 等. 弥散强化对铂基材料拉伸性能的影响[J]. 贵金属, 2020, 41(2): 1-6.
LI F, TANG H Y, WU B A, et al.Effect of Dispersion-Strengthened on Tensile Properties of Platinum-Based Materials[J]. Precious Metals, 2020, 41(2): 1-6.