Tungsten is a refractory metal with high melting point (up to 3400℃), high density (19.32g/cm3), good chemical resistance and high temperature strength. The physical and mechanical properties of refractory tungsten are listed in table 1.
Due to its good mechanical and physical properties, tungsten has become a popular structural material in engineering, and is often used to make high-temperature resistant parts. For example, it can be used as filament in light bulbs and electron tubes, anode material in X-ray tubes, heat conducting material in high temperature furnaces, rocket nozzles and heat insulation materials, military balance parts and flywheels, and tungsten carbide tool materials.
Tungsten can be made into ingot or sintered products. But their machinability is very poor. Its machining has the following characteristics:
In the process of tungsten ingot cutting, due to the coarse grain, the machining surface is rough.
Tungsten has great chemical activity and strong affinity, so it is easy to produce chip tumor in the cutting process.
Tungsten shows brittleness at room temperature, when cutting its sintered products, the chips become powder, and the hardness is very high, which aggravates the tool wear.
