Jianfeng Zhang's scientific contributions

Tungsten carbide has kindled a spark of interest because of its versatile properties for manufacturing of cutting tools. It has a broad range of applications for making the balls of ball point pen, bearings, nozzles, jewelry, ammunition, cutting and drilling tools, and electronic and mining equipment. Due to its high hardness, more than half of the WC produced annually is used for manufacturing of cutting tools. Not only the products made of this material have high hardness but also possess the advantages of high speed, wear resistance, and moderate fracture toughness. Although WC has very high hardness without binders, at room temperature, it is brittle and exhibits little or no plastic deformation. This limitation leads to the initiation of cracks and sometimes total failure. To overcome this and for the endurance of external forces, improved hardness at elevated temperatures, better fracture toughness, hindering WC tools abrasions, adhesion, oxidation, and corrosion, it is combined with some cementing material to hold its grains like cements hold the gravels in concrete. These cementing materials give strength. Thus various WC-based composites have been developed. A comprehensive review of WC-based composites has been made here, including the categories of composites, the strategy to enhance their properties, and their typical applications, besides the well-known cutting tools. The relationship between the microstructure and the properties are discussed in detail, which shows that supreme-quality WC-based composites could be achieved for advanced applications in the future. However, numerous research areas, such as densification of supercoarse WC-based composites, even distribution of WC particles, and its surface modification are still in progress.