Abstract：Silver-graphite composites are electrical contact materials with ideal comprehensive properties. In order to solve the problem of uneven distribution of graphite and weak interfacial bonding in the composites, the dense and uniform pre-copper-silver-coated graphite powder was prepared by the two-step electroless plating method of copper plating first and then silver plating on the surface of graphite, and the high performance silver-graphite composites were prepared by hot press sintering. The results show that the introduction of pre-copper plating technology can improve the distribution uniformity of graphite in the composites, reduce the pores and cracks at the interface, improve the density of the composites, furthermore, make the silver matrix form a continuous three-dimensional network structure around the graphite particles, and effectively improve the mechanical properties and electrical conductivity of the composites. Compared with the activation-silver-coated graphite composite, the hardness (HV) of the pre-copper-silver-coated graphite composite increases from 22.9 to 33.0 by 44.1%; the bending strength increases from 70.4 MPa to 97.2 MPa by 38.1%; the resistivity decreases from 0.11 μΩ·m to 0.08 μΩ·m.
张意欢, 甘雪萍, 刘超强. 镀银石墨粉制备银石墨复合材料的微观结构和性能[J]. 粉末冶金材料科学与工程, 2024, 29(1): 74-82.
ZHANG Yihuan, GAN Xueping, LIU Chaoqiang. Microstructure and properties of silver-graphite composites prepared with silver-coated graphite powders. Materials Science and Engineering of Powder Metallurgy, 2024, 29(1): 74-82.
[1] HE Y J, ISSAKA A S, YAN L J, et al.Synthesis and applications of Ag@C composites: progress and opportunity[J]. Journal of Central South University, 2022, 29(11): 3503-3528. [2] LIU Y J, YU Y T, ZHAO X M.The influence of the ratio of graphite to silver-coated copper powders on the electromagnetic and mechanical properties of single-layer coated composites[J]. Journal of the Textile Institute, 2021, 112(11): 1709-1716. [3] WANG X D, ZHOU H, WEI Y P, et al.Electrical explosion spray of Ag/C composite coating and its deposition behavior[J]. Ceramics International, 2022, 48(4): 4497-4504. [4] KUMAR B, VERMA D K, SHUKLA N, et al.Ionic liquid stabilized Ag@C composite for improvement of triboactivity[J]. Journal of Molecular Liquids, 2020, 307: 113012. [5] WANG J, FENG Y, ZHANG X B, et al.Effects of graphite content on the contact voltage drop of CNTs-Ag-G composites[J]. Rare Metal Materials and Engineering, 2008, 37(5): 835-839. [6] LIU J, JIANG P P, HE C, et al.Preparation and characterization of Ag@C composites with hexagon silver core and controllable carbon shell for surface-enhanced Raman scattering[J]. Journal of Materials Science, 2018, 53(5): 3443-3454. [7] PIETRZAK K, FRYDMAN K, WÓJCIK-GRZYBEK D, et al. Effect of carbon forms on properties of Ag-C composites contact materials[J]. Materials Science- Medziagotyra, 2018, 24(1): 69-74. [8] EDTMAIER C, HULA R C.Thermo-physical properties of silver/carbon fibre composites[J]. International Journal of Materials Research, 2010, 101(9): 1105-1112. [9] FENG Y, YUAN H L, ZHANG M.Fabrication and properties of silver-matrix composites reinforced by carbon nanotubes[J]. Materials Characterization, 2005, 55(3): 211-218. [10] JIANG P, LI F, WANG Y P.Effect of different types of carbon on microstructure and arcing behavior of Ag/C contact materials[J]. IEEE Transactions on Components and Packaging Technologies, 2006, 29(2): 420-423. [11] 朱振国, 于冬, 张志宇, 等. 继电器触头用浸银石墨复合材料的研制与性能[J]. 炭素技术, 2022, 41(5): 72-75. ZHU Zhenguo, YU Dong, ZHANG Zhiyu, et al.Preparation and properties of silver-impregnated graphite composites for electrical contact of relays[J]. Carbon Techniques, 2022, 41(5): 72-75. [12] WANG Y R, GAO Y M, TAKAHASHI J, et al.Investigation of modification of Cu-Ni-graphite composite by silver[J]. Materials Chemistry and Physics, 2020, 239: 121990. [13] 魏芳. 液态金属在石墨表面润湿的研究现状[J]. 甘肃科技, 2019, 35(1): 32-35. WEI Fang.Research status of liquid metal wetting on graphite surface[J]. Gansu Science and Technology, 2019, 35(1): 32-35. [14] HONG S H, LEE W G.Preparation and characterization of expanded graphite/Ag nanoparticle composites for the improvement of thermal diffusion[J]. Korean Chemical Engineering Research, 2018, 56(3): 410-415. [15] ZHANG Y, XING C S, JIANG D L, et al.Facile synthesis of core-shell-satellite Ag/C/Ag nanocomposites using carbon nanodots as reductant and their SERS properties[J]. Crystengcomm, 2013, 15(32): 6305-6310. [16] 王卓健. 基于石墨表面改性SiC涂层的制备及性能研究[D]. 南昌: 南昌大学, 2022. WANG Zhuojian.Preparation and performance study of graphite based on surface modified SiC coatings[D]. Nanchang: Nanchang University, 2022. [17] JIA D M, MA J B, GAN X P, et al.A comparison study of Ag composites prepared by spark plasma sintering and hot pressing with silver-coated CNTs as the reinforcements[J]. Materials, 2019, 12(12): 1949. [18] JANG J H, PARK H K, LEE J H, et al.Thermal properties of silver/graphite composites with different volume ratio processed by pulsed current activated sintering method[J]. Advanced Composite Materials, 2021, 30(3): 259-270. [19] ZHENG J W, WANG Z L, LIANG Q, et al.Fabrication of Ag-C composite materials with core-shell structure[J]. Applied Surface Science, 2014, 313: 346-351. [20] HOU C P, ZHANG H, MA Y, et al.Structure and performance of spherical natural graphite modified by Ag-C double coating[J]. International Journal of Electrochemical Science, 2017, 12(5): 3652-3661. [21] YUAN Y, GAN X P, LAI Y T, et al.Microstructure and properties of graphite/copper composites fabricated with Cu-Ni double-layer coated graphite powders[J]. Composite Interfaces, 2020, 27(5): 449-463. [22] 赖远腾, 甘雪萍, 肖柱, 等. 石墨表面镀镍对石墨/铜复合材料微观结构和力学性能的影响[J]. 粉末冶金材料科学与工程, 2018, 23(5): 495-502. LAI Yuanteng, GAN Xueping, XIAO Zhu, et al.Effects of Ni-coated graphite particles on microstructure and properties of graphite/copper composites[J]. Materials Science and Engineering of Powder Metallurgy, 2018, 23(5): 495-502.
2024, Vol. 29 
