Machining of tungsten alloys

Tungsten tubing can be produced by direct extrusion from sintered billets. Extruded billets or slurry-extruded sintered billets can also be spun. Spinning can also produce shaped tungsten products. Large-diameter bars are mostly produced using extrusion or rolling processes.

Machining

Tungsten is hard and notch-sensitive, making machining difficult and requiring carbide tools. To prevent cutting cracks, the workpiece is often heated above the plastic-brittle transition temperature before cutting, and the cutting procedure must be strictly controlled. Tungsten grinding requires light grinding with specific types of grinding wheels and cooling; otherwise, cracking will occur. Tungsten sheets thicker than 0.2 mm must be preheated before stamping and shearing. Sheets exceeding a certain thickness cannot be sheared and often require grinding with a grinding wheel.

Sheet Rolling

Tungsten sheet rolling can be divided into hot rolling, warm rolling, and cold rolling. Due to the high deformation resistance of tungsten, ordinary rolls cannot fully meet the requirements of tungsten sheet rolling; special material rolls must be used. During rolling, the rolls must be preheated. Depending on the rolling conditions, the preheating temperature ranges from 100 to 350°C. The billet can only be processed when its relative density (the ratio of actual density to theoretical density) is greater than 90%. The billet has good processing performance when its density is between 92% and 94%.