Influence of Milling Time on Preparation of Ultrafine WC-Co Composite Powder and Its Refinement Mechanism

被引：0

作者：

Zhong T. ^{[1
]}

Hu D. ^{[1
]}

Zhang L. ^{[1
]}

Shi A. ^{[2
]}

Huang Y. ^{[3
]}

Liu B. ^{[2
]}

机构：

[1] College of Applied Science, Jiangxi University of Science and Technology, Ganzhou

[2] Institute of Research and Engineering, Jiangxi University of Science and Technology, Ganzhou

[3] Ganzhou Zhixin Mining Ltd., Co., Ganzhou

来源：

Xiyou Jinshu/Chinese Journal of Rare Metals | 2020年 / 44卷 / 03期

关键词：

Ball-milling; Cemented carbides; Reduced carburization; WC-Co composite powder;

D O I：

10.13373/j.cnki.cjrm.XY18110004

中图分类号：

学科分类号：

摘要：

Influence of milling time on the aspect ratio of WO2.72 rods and the particle size of WC-Co composite powder was studied. The refinement mechanism of WC-Co particles was obtained by observing the microstructure of intermediate in the reduced carburization process. Phases and microstructures of powder obtained at each stage were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results showed that the average diameter of WO2.72 rods decreased when the milling time increased, while the mean length of WO2.72 rods became longer with the increasing of milling time. When milling time was 40 h, the average diameter and the average length of WO2.72 rods were 142 nm and 6.95 μm, respectively. After reduced carburization, the as-synthesized ultrafine WC-Co composite powder had a homogeneous particle size distribution with the average size of about 126 nm. As-synthesized WO2.72 rods with large aspect ratio interlace each other to form interconnected pores, which made WO2.72 rods have good permeability. During reduction process, reductive gas could easily enter into WO2.72 rods inside, which could reduce atom diffusion distance and greatly shorten reduction reaction time. At the same time, the production of water vapor could overflow to outside and it inhibited growth trend of the particles. The reduced carburization process was controlled by solid-state local chemical reaction mechanism. Therefore, the particle size of WC-Co composite powders was determined by the diameter of WO2.72 rods. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.

引用

页码：287 / 294

页数：7

共 18 条

[1] He M., Wang J.Y., He R.G., Yang H.L., Ruan J.M., Effect of cobalt content on the microstructure and mechanical properties of coarse grained WC-Co cemented carbides fabricated from chemically coated composite powder, Journal of Alloys and Compounds, 766, (2018)
[2] Norgren S., Garc A.J., Blomqvist A., Yin L., Trends in the P/M hard metal industry, International Journal of Refractory Metals and Hard Materials, 48, (2015)
[3] Fang Z.Z., Wang H., Kumar V., Coarsening, densification and grain growth during sintering of nano-sized powders-a perspective, International Journal of Refractory Metals and Hard Materials, 62, (2017)
[4] Chen Q., Qin M.L., Chen P.Q., Huang M., Li R., Zhao S.J., Qu X.H., WC-Co-Cr<sub>3</sub>C<sub>2</sub>-VC nanocomposite powders fabricated by solution combustion synthesis and carbothermal reduction, Ceramics International, 43, (2017)
[5] Liu B.X., Shi A.H., Yang G.L., Su Q., Chen G.J., Zhang L.N., Yang B., Recovery of tungsten carbides for preparing ultrafine WC-Co composite powder using core-shell structured precursor synthesized by CVD, International Journal of Refractory Metals and Hard Materials, 67, (2017)
[6] Liu X.M., Zhang J.L., Hou C., Wang H.B., Song X.Y., Nie Z.R., Mechanisms of WC Plastic Deformation in Cemented Carbide, Materials & Design, 150, (2018)
[7] He R.G., Wang J.Y., He M., Synthesis of WC composite powder with nano-cobalt coatings and its application in WC-4Co cemented carbide, Ceramics International, 44, (2018)
[8] Yang Q.M., Yang J.G., Wen Y., Zhang Q.Y., Chen L.Y., Chen H., A novel route for the synthesis of ultrafine WC-15 wt%Co cemented carbides, Journal of Alloys and Compounds, 748, (2018)
[9] Liu B.X., Shi A.H., Su Q., Chen G.J., Li W., Zhang L.N., Yang B., Recovery of tungsten carbides for preparing ultrafine WC-Co composite powder by two-step reduction process, Powder Technology, 306, (2017)
[10] He W., Tan D.Q., Kuang H., Li Y.L., Yang X., Zhu H.B., Effect of yttrium barrier on the preparation of precursor powders of WC-Co cemented carbide and properties of sintered bulk, Journal of Alloys and Compounds, 742, (2018)

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