Microstructure and properties of laser clad WC/TiC/Co coating on YG8 cemented carbide surface

doi:10.13251/j.issn.0254-6051.2021.12.027

Abstract

Abstract: WC/TiC/Co coating on YG8 cemented carbide surface was prepared by laser cladding, and the microstructure and the phase composition were analyzed by means of scanning electron microscope(SEM), energy disperse spectroscopy(EDS) and X-ray diffraction(XRD), respectively. In addition, microhardness, hardness distribution and wear resistance were measured or tested. The results show that the coating surface is flat and bonded to the matrix tightly, the cross section morphology is fine without obvious defects. WC particles can be find in surface layer and edges while disappear in clad layer, and new homogeneous microstructure is observed in clad layer. In heat affected zone, WC grains take place recrystallization and gather because of heat effect of laser. The phases in clad layer are mainly composed of WC, W₂C, (Ti,W)C_1-x, M₆C(Co₄W₂C, Co₃W₃C), etc, which result in dispersion strengthening, greatly enhance the performance of the coating. After detection, the microhardness of the clad layer distributes in the range of 1700-1800 HV0.5, and the maximum reaches 1783 HV0.5, which is obviously higher than the common YG8 cemented carbide, while the microhardness of heat affected zone and matrix is slightly decreased. Wear resistance of the clad layer is heightened effectively, compared with the YG8 cemented carbide, wear volume is reduced by 90.67%, average friction coeffiaiont is 0.293, and the abrasive wear is major wear mechanism.

Key words: laser cladding, WC/TiC/Co coating, microstructure, microhardness, wear resistance

CLC Number:

Liang Weiyin, Liang Guoxing, Dong Lijun, Liu Donggang, Wang Shiying. Microstructure and properties of laser clad WC/TiC/Co coating on YG8 cemented carbide surface[J]. Heat Treatment of Metals, 2021, 46(12): 168-174.

References

[1]赵岁春, 刘宁, 陈爱华. TiC对WC-13Co细晶粒硬质合金组织和性能的影响[J]. 材料热处理学报, 2018, 39(1): 45-50.
Zhao Suichun, Liu Ning, Chen Aihua. Effect of titanium carbide on microstructure and properties of fine grain WC-13Co cemented carbides[J]. Transactions of Materials and Heat Treatment, 2018, 39(1): 45-50.
[2]王丽利, 李海艳, 刘宁. 添加TiC对WC-Co基硬质合金组织和力学性能的影响[J]. 热处理, 2010, 25(3): 25-30.
Wang Lili, Li Haiyan, Liu Ning. Effect of TiC on microstructures and mechanical properties of WC-Co-based carbides[J]. Heat Treatment, 2010, 25(3): 25-30.
[3]Weidow J, Zackrisson J, Bo J, et al. Characterisation of WC-Co with cubic carbide additions[J]. International Journal of Refractory Metals and Hard Materials, 2009, 27(2): 244-248.
[4]Ren X Y, Miao H Z, Peng Z J. A review of cemented carbides for rock drilling: An old but still tough challenge in geo-engineering[J]. International Journal of Refractory Metals and Hard Materials, 2013, 39: 61-77.
[5]周书助. 硬质合金生产原理和质量控制[M]. 北京: 冶金工业出版社, 2014.
[6]储开宇. 我国硬质合金产业的发展现状与展望[J]. 稀有金属与硬质合金, 2011, 39(1): 52-56.
Chu Kaiyu. The latest development and prospect of cemented carbide industry in China[J]. Rare Metals and Cemented Carbides, 2011, 39(1): 52-56.
[7]关振中. 激光加工工艺手册[M]. 北京: 中国计量出版社, 1998.
[8]张津超, 石世宏, 龚燕琪, 等. 激光熔覆技术研究进展[J]. 表面技术, 2020, 49(10): 1-11.
Zhang Jinchao, Shi Shihong, Gong Yanqi, et al. Research progress of laser cladding technology[J]. Surface Technology, 2020, 49(10): 1-11.
[9]刘寿荣. WC-Co硬质合金γ相相变[J]. 稀有金属, 2000(2): 101-105.
Liu Shourong. Binder phase transformation in WC-Co cemented carbides[J]. Chinese Journal of Rare Metals, 2000(2): 101-105.
[10]李闯, 刘洪喜, 张晓伟, 等. 40Cr刀具钢表面激光熔覆钴基碳化物复合涂层的组织与性能[J]. 中国激光, 2015, 42(11): 53-58.
Li Chuang, Liu Hongxi, Zhang Xiaowei, et al. Microstructure and property of Co-based carbide composite coating fabricated by laser cladding on 40Cr tool steel surface[J]. Chinese Journal of Lasers, 2015, 42(11): 53-58.
[11]Yamaguchi T, Hagino H. Effects of the ambient oxygen concentration on WC-12Co cermet coatings fabricated by laser cladding[J]. Optics and Laser Technology, 2021, 139(3): 106922.
[12]Wang Q, Li L X, Yang G B, et al. Influence of heat treatment on the microstructure and performance of high-velocity oxy-fuel sprayed WC-12Co coatings[J]. Surface and Coatings Technology, 2012, 206(19/20): 4000-4010.
[13]Khameneh A S, Heydarzadeh S M, Hokamoto K, et al. Effect of heat treatment on wear behavior of HVOF thermally sprayed WC-Co coatings[J]. Wear, 2006, 260(11/12): 1203-1208.
[14]刘洪喜, 董涛, 张晓伟, 等. 激光熔覆制备WC/Co50/Al硬质合金涂层刀具的微观结构及切削性能[J]. 中国激光, 2017, 44(8): 104-112.
Liu Hongxi, Dong Tao, Zhang Xiaowei, et al. Microstructure and cutting performance of WC/Co50/Al cemented carbide coated tools fabricated by laser cladding process[J]. Chinese Journal of Lasers, 2017, 44(8): 104-112.
[15]张立, 王喆, 陈述, 等. 过渡族金属碳化物在WC-Co硬质合金中的界面偏析与固溶行为[J]. 硬质合金, 2014, 31(1): 49-59.
Zhang Li, Wang Zhe, Chen Shu, et al. Boundary segregation and solid solution behaviors of transitional metal carbides in WC-Co cemented carbides[J]. Cemented Carbide, 2014, 31(1): 49-59.
[16]王忠华, 刘宜强, 余音宏, 等. 热处理条件对WC-Co涂层性能的影响[J]. 稀有金属与硬质合金, 2020, 48(5): 23-28.
Wang Zhonghua, Liu Yiqiang, Yu Yinhong, et al. Effect of heat treatment conditions on properties of WC-Co coating[J]. Rare Metals and Cemented Carbides, 2020, 48(5): 23-28.