Two-Step Spark Plasma Sintering Process of Ultrafine Grained WC-12Co-0.2VC Cemented Carbide

Zhenhua Wang; Jiheng Jia; Boxiang Wang; Yulin Wang

doi:10.3390/ma12152443

Two-Step Spark Plasma Sintering Process of Ultrafine Grained WC-12Co-0.2VC Cemented Carbide

Materials (Basel). 2019 Jul 31;12(15):2443. doi: 10.3390/ma12152443.

Authors

Zhenhua Wang¹, Jiheng Jia², Boxiang Wang², Yulin Wang³

Affiliations

¹ School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. wzh1980@njust.edu.cn.
² School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
³ School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. wyl_sjtu@njust.edu.cn.

Abstract

Ultrafine grained WC-12Co-0.2VC (named UYG12V) cemented carbides were prepared via the two-step spark plasma sintering (SPS) in this study. First, the effects of the sintering temperature on the relative density and WC grain size of UYG12V cemented carbides were studied. The results show that regular WC grains form when sintered at 1300 °C. The sintered body begins to rapidly densify and WC grains grow slowly when sintered at 1200 °C. Thus, the first-step (T1) and the second-step (T2) temperatures in the two-step SPS of UYG12V are 1300 °C and 1200 °C, respectively. The effect of the holding time during the first and second steps on the mechanical properties was also studied. The results show that the UYG12V cemented carbide sintered at 1300 °C for 3 min and then at 1200 °C for 5 min has the best comprehensive mechanical properties, exhibiting the average particle size, Vickers hardness, fracture toughness, relative density, and bending strength of 271 nm, 18.06 GPa, 12.25 MPa m^1/2, 99.49%, and 1960 MPa, respectively.

Keywords: cemented carbide; relative density; spark plasma sintering; two-step; ultrafine grain.

Abstract

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