It is a gray-black metal with metallic luster (body-centered cubic crystal). Melting point 3400 ℃. Boiling point 5555℃. The hardness of tungsten is the hardest among metals. The hardness of the sintered
Tungsten Rod is 200~250, and the tungsten rod passed through the rotary hammer is 350~400. Soluble in mixed acid of nitric acid and hydrofluoric acid. Melt with a mixture of sodium hydroxide and sodium carbonate. Slightly soluble in nitric acid, sulfuric acid, aqua regia; insoluble in water, hydrofluoric acid, potassium hydroxide. Tungsten is available in two variants, a and B. At standard temperature and atmospheric pressure, type a is a stable body-centered cubic structure. Type B tungsten can only appear in the presence of oxygen. It is stable below 630 °C, and is converted into a-tungsten above 630 °C, and this process is irreversible. Tungsten is mostly used in the production of cemented carbide and ferrotungsten. Tungsten and chromium, molybdenum and cobalt form heat-resistant and wear-resistant alloys for making tools, metal surface hardening materials, gas turbine blades and combustion tubes, etc. Tungsten and tantalum, niobium, molybdenum, etc. form refractory alloys. Tungsten copper and tungsten silver alloys are used as electrical contact materials. High-density tungsten-nickel-copper alloy is used as a radiation shield. Metal tungsten wires, rods, sheets, etc. are used to make parts of light bulbs, electronic tubes and electrodes for arc welding.
Tungsten Powder can be sintered into filters of various porosity. FW-1 is used as raw material for large slab and tungsten-rhenium galvanic couple. FW-2 is used for contact alloy, high specific gravity shielding material. FWP-1 is used for plasma sprayed materials.
Tungsten powder is the main raw material for processing powder metallurgy tungsten products and tungsten alloys. Pure tungsten powder can be made into wire, rod, tube, plate and other processed materials and certain shaped products. Tungsten powder mixed with other metal powders can be made into various tungsten alloys, such as tungsten-molybdenum alloy, tungsten-rhenium alloy, tungsten-copper alloy and high-density tungsten alloy. Another important application of tungsten powder is to make tungsten carbide powder, and then prepare cemented carbide tools, such as turning tools, milling cutters, drills and molds.
