1. Fabrication and characterization of ultrafine WC-10CoCrNiCuFe cemented carbides.
- Author
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Zou, Qin, Ren, Haibo, Li, Yanguo, Xiong, Jianchao, and Luo, Yongan
- Subjects
POWDERS ,FACE centered cubic structure ,MECHANICAL alloying ,VICKERS hardness ,TUNGSTEN carbide ,CARBIDES ,FRACTURE toughness - Abstract
• After ball milling, the average size of HEA powder composed of large particles and small particles is about 7.1 µm and 1 µm, respectively, and the average size of WC particles is about 368.5 nm. The microstructure consists of FCC phase, HCP-WC phase, Cr 2 O 3 and η(Fe,Co) 3 W 3 C phase. • The interface characteristics of the WC/HEA system include the FCC(111)//HCP (10 1 ‾ 1) interface with stable ionic bond and the interface that reacts due to the formation of (Fe, Co) 3 W 3 C phase. • The density, hardness and fracture toughness values of WC-10 wt% HEA cemented carbide are 14.38 g/cm
3 , 1988.60 HV, 10.98 MPa m1/2 , and the compressive strength values at room temperature and 800 ℃ are 3307 MPa and 1747 MPa, respectively. The thermal conductivities at 50 °C and 650 °C were 38 W(m K)−1 and 30.4 W(m K)−1 , respectively. The metal oxides generated by friction behavior at 500 °C have a good effect of reducing friction and antiwear, with an average friction coefficient of 0.365. A new ultra-fine tungsten carbide (WC) cemented carbide was fabricated by spark plasma sintering (SPS), in which the CoCrNiCuFe high entropy alloy (HEA) was used as the binder and was mixed with WC carbide through the mechanical ball milling method. The microstructure of WC-10 wt% HEA composites was investigated through scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and differential scanning calorimetry-thermogravimetric analysis (DSC-TG). The results show that the interface characteristics of the WC/HEA system include the FCC(111)//HCP (10 1 ¯ 1) interface with stable ionic bonds and the interface that reacts due to the formation of the (Fe, Co) 3 W 3 C phase. The mechanical properties of WC-10 wt% HEA composites were investigated through the Vickers hardness test, friction and wear tests, and compression test. The WC-10 wt% HEA composites exhibit good fracture toughness and hardness of 10.98 MPa m1/2 and 1988.60 HV 30 , respectively. The compressive strength at room temperature and 800 °C is up to 3307 and 1747 MPa, respectively. The composites exhibited excellent properties attributed to the good wettability of HEA on WC grains and the consequent strengthening effect on the WC/WC interfaces. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2024
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