In this work, the ultra-fine grain WC-10Co alloys were prepared through a two-step sintering process comprising steps of low-temperature sintering for a long time and high-temperature sintering for a short time. The effects of sintering methods (one-step/two-step sintering) on the microstructure, density, grain size and performance of WC-10Co hard metals with or without VC addition were investigated. The densities of all samples were lower than 97.0% in one-step sintering. After two-step sintering, the relative densities of all samples were increased, and those of the samples without VC were higher than 98.5%. In addition, there are a large number of grains with a high aspect ratio in the samples without VC. The pure WC-10Co alloy showed the best comprehensive mechanical properties after long-time (2 hours) sintering at a low temperature (1300 °C) and short-time (10 minutes) sintering at a high temperature (1450 °C), and the grain size, hardness and toughness of the sample were 0.70 μm, 15.35 GPa and 13.54 MPa·m1/2, respectively. The grain size of the sample containing 0.5 wt.% VC was only 0.26 μm under the same sintering conditions, which showed a high hardness of 18.14 GPa and a toughness of 8.56 MPa·m1/2.
WangHBGeeMQiuQF, et al.Grain size effect on wear resistance of WC-Co cemented carbides under different tribological conditions. J Mater Sci Technol2019; 35: 2435–2446.
2.
WeiCBSongXYFuJ, et al.Effect of carbon addition on microstructure and properties of WC-Co cemented carbides. J Mater Sci Technol2012; 28: 837–843.
3.
LealEADGomesUUAlvesSM, et al.The influence of powder preparation condition on densification and microstructural properties of WC-Co-Al2O3 cermets. Int J Refract Met Hard Mater2020; 92: 105275.
4.
GaoYYanMYLuoBH, et al.Effects of NbC additions on the microstructure and properties of non-uniform structure WC-Co cemented carbides. Mater Sci Eng A2017; 687: 259–268.
5.
PengYWangHBZhaoC, et al.Nanocrystalline WC-Co composite with ultrahigh hardness and toughness. Compos Pt B-Eng2020; 197: 108161.
6.
SunLYangTEJiaCC, et al.VC, Cr3C2 doped ultrafine WC-Co cemented carbides prepared by spark plasma sintering. Int J Refract Met Hard Mater2011; 29: 147–152.
7.
ChaSIHongSHHaGH, et al.Mechanical properties of WC-10Co cemented carbides sintered from nanocrystalline spray conversion processed powders. Int J Refract Met Hard Mater2001; 19: 397–403.
8.
CaiHJingWWGuoSD, et al.Effects of micro/nano CeO2 on the microstructure and properties of WC-10Co cemented carbides. Int J Refract Met Hard Mater2021; 95: 105432.
9.
LiJFChengJGWeiBZ, et al.Preparation and performance of ultrafine grained WC-10Co alloys with added La2O3. Ceram Int2019; 45: 3969–3976.
10.
YangYLuoLMZanX, et al.Synthesis of Y2O3-doped WC-Co powders by wet chemical method and its effect on the properties of WC-Co cemented carbide alloy. Int J Refract Met Hard Mater2020; 92: 105324.
11.
GuoSDYanWYiJH, et al.The optimization of mechanical property and corrosion resistance of WC-6Co cemented carbide by Mo2C content. Ceram Int2020; 46: 17243–17251.
12.
WuCCChangSHTangTP, et al.Study on the properties of WC-10Co alloys adding Cr3C2 powder via various vacuum sintering temperatures. J Alloy Compd2016; 686: 810–815.
13.
OkadaKOsadaA. Microstructural study on the grain growth inhibition of VC-doped WC-Co cemented carbides. Int J Refract Met Hard Mater2017; 62: 149–154.
14.
DengXCWangKFZhangGH. Effects of oxide addition on structure and properties of WC-10Co cemented carbide obtained by in situ synthesized powder. Int J Appl Ceram Technol2022; 19: 1916–1928.
15.
WangBXWangZHYinZB, et al.Preparation and properties of the VC/Cr3C2/TaC doped ultrafine WC-Co tool material by spark plasma sintering. J Alloy Compd2020; 816: 152598.
16.
XiaoDHHeYHLuoWH, et al.Effect of VC and NbC additions on microstructure and properties of ultrafine WC-10Co cemented carbides. Trans Nonferrous Met Soc China2009; 19: 1520–1525.
17.
GarcíaJCiprésVCBlomqvistA, et al.Cemented carbide microstructures: a review. Int J Refract Met Hard Mater2019; 80: 40–68.
18.
KumarDSinghK. High hardness-high toughness WC-20Co nanocomposites: effect of VC variation and sintering temperature. Mater Sci Eng A2016; 663: 21–28.
19.
LiJChengJChenP, et al.Fabrication of WC-Co cemented carbides with gradient distribution of WC grain size and Co composition by lamination pressing and microwave sintering. Ceram Int2018; 44: 11225–11232.
20.
SunJZhaoJLiZ, et al.Effects of initial particle size distribution and sintering parameters on microstructure and mechanical properties of functionally graded WC-TiC-VC-Cr3C2-Co hard alloys. Ceram Int2017; 43: 2686–2696.
21.
GuoXGZhengYZhangGT, et al.Microstructure and mechanical properties of TiC steel-bonded carbides prepared by two-step sintering technique. Int J Refract Met Hard Mater2020; 93: 105342.
22.
WangBXJiaJHWangZH, et al.Fabrication and performance of graded ultrafine WC-Co cemented carbide tool by one/two-step spark plasma sintering. Ceram Int2021; 47: 8322–8329.
23.
WangKFYangXHChouKC, et al.Preparation of nano-scaled WC powder by low-temperature carbothermic reduction method. Int J Refract Met Hard Mater2022; 102: 105724.
24.
WuKHJiangYJiaoSQ, et al.Synthesis of high purity nano-sized transition-metal carbides. J Mater Res Technol2020; 9: 11778–11790.
25.
MaCAChuYQHuangH, et al.Composition and phase transformation of WC-co cemented carbide. J Zhengjiang Univ Technol2003; 31: 1–6.
26.
BergerSPoratRRosenR. Nanocrystalline materials: a study of WC-based hardmetals. Prog Mater Sci1997; 42: 311–320.
27.
LinH. Preparation of nanosized WC, VC and its composite powders and characterization of their sintered block properties. Chengdu, Sichuan Province, China: University of Electronic Science and Technology of China, 2014.
28.
ShettyDKWrightIGMincerPN, et al.Indentation fracture of WC-Co cermets. J Mater Sci1985; 20: 1873–1882.
29.
DengXCZhangHZhangGH. Effect of CeO2 and VC co-doping on the microstructure and properties of WC-10Co cemented carbide. Int J Refract Met Hard Mater2022; 108: 105938.
30.
AcharyaSDebataMAcharyaTS, et al.Influence of nickel boride addition on sintering behaviour and mechanical properties of TiC-Ni based cermets. J Alloy Compd2016; 685: 905–912.
31.
SunXGWangYLiDY. Mechanical properties and erosion resistance of ceria nano-particle-doped ultrafine WC-12Co composite prepared by spark plasma sintering. Wear2013; 301: 406–414.
32.
DengXCZhangGH. Effects of sintering method and Al2O3 content on microstructure and mechanical properties of WC-10Co cemented carbide. Int J Refract Met Hard Mater2024; 124: 106812.
33.
KeZZhengYZhanGT, et al.Fabrication of dual-grain structure WC-Co cemented carbide by in-situ carbothermal reduction of WO3 and subsequent liquid sintering. Ceram Int2020; 46: 12767–12772.
34.
LuZYJinDSunYJ, et al.Effect of ultrafine WC contents on the microstructures, mechanical properties and wear resistances of regenerated coarse grained WC-10Co cemented carbides. Int J Refract Met Hard Mater2021; 97: 105516.
35.
KeZZhengYZhanGT, et al.Microstructure and mechanical properties of dual-grain structured WC-Co cemented carbides. Ceram Int2019; 45: 21528–21533.
36.
LlanesLTorresYAngladaM. On the fatigue crack growth behavior of WC-Co cemented carbides: kinetics description, microstructural effects and fatigue sensitivity. Acta Mater2002; 50: 2381–2393.
37.
ZhengDHLiXQAiX, et al.Bulk WC-Al2O3 composites prepared by spark plasma sintering. Int J Refract Met Hard Mater2012; 30: 51–56.
38.
OuXQXiaoDHShenTT, et al.Characterization and preparation of ultra-fine grained WC-Co alloys with minor La-additions. Int J Refract Met Hard Mater2012; 31: 266–273.
39.
SivaprahasamDChandrasekarSBSundaresanR. Microstructure and mechanical properties of nanocrystalline WC-12Co consolidated by spark plasma sintering. Int J Refract Met Hard Mater2007; 25: 144–152.
40.
YinCRuanJMDuY, et al.Effects of Cr3C2, VC, and TaC on microstructure, WC morphology and mechanical properties of ultrafine WC-10wt.% Co cemented carbides. Metals (Basel)2020; 10: 1211.
