The most common definition of refractory metals includes five elements: niobium, molybdenum, tantalum, tungsten, and rhenium. They share some properties, including a melting point above 2000 °C and high hardness at room temperature. Their machineabilities are quite different, we will introduce the processed & applications for these metal in solid bar form here.
Most common processing for refractory mental is sintering, that is press powder or mixed powder into certain shape, sintered in vacuum sintering furnace. This forms simply sintered metal blanks. Different temperature & sintering time is used for different material and dimensions. Simply sintered metal bars are basically used as additive in stainless steel and other no-ferrous alloys, to improve the properties. It only requires purity and limits gas elements for this usage.
Other applications which requires the material to be more dense, uniform grain, better machinability, resistance on temperature & wear. Forging, & repeat forging can make the material suitable for these applications. Metal bars can be forged from ingots, or smaller bars are cut from plates. Below we listed the applications for forged metal bars.
Tungsten bar application: to make emission cathodes, high temperature forming bars, support wires, printer pins, various electrodes, stainless steel additives, heating elements of quartz furnace, etc. They are also engaged in guns, rockets, satellites, airplanes and ships.