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.
Niobium bar application: Electronic industry, chemistry, electronic industry, steel, ceramics, electronics, nuclear energy industries, and superconductor technology; melted cast ingots and alloying agents. Widely used in manufacturing various kinds of alloy steel, high temperature alloy, optical glass, cutting tool, electronics and superconducting materials and other industries.
Molybdenum bar application: Produce crucible for all the traditionally utilized procedures in the field of sapphire development, utilized as upgraded dissolving and cementing vessels, a wide range of glass liquefy, high power densities and the progression of power through power diodes and transistors create heat. molybdenum and its compounds are the ideal substrate for power hardware. At the point when utilized as a base plate, molybdenum dependably disseminates heat. Also, used as in other high temperature furnaces.
Based on different physical properties, Mechanical properties, Chemical properties, Machinability, Recrystallization behavior. Molybdenum alloys with various scopes of properties which are unequivocally built to meet the necessities of every individual application.
Tantalum bar application: Most important properties of tantalum are corrosion resistance & high melting point, it can be used any surroundings required these properties if not consider cost factor. Tantalum is a bit expensive compare to other refractory metals, this makes it is considered for extreme environments.
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.
Rhenium bar is commonly used in the production of high temperature materials, super alloy additives and high temperature fields such as aerospace
Niobium & tantalum materials have much better ductility than molybdenum & tungsten, while tungsten has the poorest ductility & machineability amount all refractory metals. Our main non-ferrous metals are refractory metals, which are extraordinarily resistant to heat and wear. They are mostly used in the materials science, metallurgy and engineering, etc.
https://www.etimaterials.org/molybdenum/molybdenum-bar/
https://www.etimaterials.org/tantalum/
https://www.etimaterials.org/tungsten/tungsten-bar-2/