In steel industry tungsten carbide coatings used for example for guide rollers. Applications of tungsten carbide metal matrix composites are found in the mining industry to coat different drilling and digging parts, in agriculture for coating on plough shares, tillage equipment and cutters. Tungsten carbide used in producing critical components such as spray injection nozzle, sand blasting nozzle, guide sleeve in machines, micrometre anvil, centre for lathe and grinder, rock cutting drill bit, etc. But there are few challenges associated in developing binderless WC–W 2C composite for fully densifying the sintered body together for achieving a high hardness and toughness composite.
Hence to meet industrial requirement, it is required to prepare binder less WC–W 2C composite with improved microstructural and mechanical properties.
Hence though metallic binder increases toughness but it hampers hardness behaviour of tungsten carbide ceramic. for WC-10 wt% Co sample showing hardness of 1333 VHN. Similar kind of result was also obtained by Almond et al. When 10 wt% Co is added to WC (relative density-98.9%) the fracture toughness increases from 6.6 to 11.6 MPa m 1/2 in expense of decrease in hardness from 2486 to 1756 VHN. Kim and co-workers reported hardness of binderless WC to be 2486 VHN with 97.6 relative density (%). The mono carbide of tungsten (WC) characterized with superior properties like high melting point (2750 ☌) and high hardness (16–22 GPa). The authors have taken advantage of such a decomposition to prepare WC–W 2C composite at three different compositions by arc plasma melt casting of W and WC pellets prepared from their powder mixture mixed at different proportions. W–C Phase diagram indicates a pseudo-eutectic point at 2530 ☌ which follows eutectoid decomposition below 2380 ☌ to form a mixture of WC and W 2C (Fig. For industrial practice fused tungsten carbide- a composite of WC and W 2C is produced by melting and followed by cooling of up to room temperature. While some literature report higher hardness for WC, the recent ones mention higher hardness for W 2C. Tungsten carbide generally occurs in two phases, viz.
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