Tungsten carbide (WC) is a compound composed of the refractory metal tungsten and non-metal carbon, characterized by high density, high melting point, high strength, exceptional hardness, high-temperature resistance, corrosion resistance, wear resistance, and good electrical and thermal conductivity. These properties make it an ideal tool material.
However, pure WC powder has significant drawbacks, such as high brittleness and poor toughness. To produce cemented carbide tools with superior overall performance, it is often necessary to incorporate appropriate binders, such as cobalt (Co), nickel (Ni), chromium (Cr), molybdenum (Mo), titanium (Ti), or copper (Cu).
Specifically, cemented carbide with WC powder as the hard phase and Co as the binder phase is particularly suitable for cutting tools. Its excellent thermal conductivity facilitates the dissipation of cutting heat from the tool tip, reducing tip temperature and preventing overheating and softening. Additionally, its high bending strength and impact toughness effectively minimize the likelihood of chipping during cutting. With superior cutting resistance (far exceeding high-speed steel), it can be ground to form sharp cutting edges.
Cemented carbide with WC powder as the hard phase and Ni as the binder phase is more suitable for corrosion-resistant components. Its corrosion resistance surpasses that of WC-Co cemented carbide tools, making it ideal for environments with various corrosive media. Furthermore, WC-Ni cemented carbide seals are suitable for applications in low-temperature, high-temperature, vacuum, and high-pressure conditions.
Cemented carbide composed of WC, TiC, and Co exhibits high hardness, excellent heat resistance, high compressive strength, good oxidation resistance, but relatively poor thermal conductivity, making it suitable for machining steel.
It should be noted that the specific physical properties of cemented carbide vary depending on the raw material composition. By applying one or more layers of refractory compounds, such as carbides or nitrides, to the surface of cemented carbide, its high wear resistance and toughness can be further enhanced, making it more suitable for high-speed cutting applications.
