Tungsten alloy is an alloy based on tungsten and composed of other elements. In metal, tungsten has the highest melting point, high temperature strength and creep resistance and thermal conductivity, conductive and electron emission performance are good, than major, in addition to a large number of used in the manufacture of cemented carbide and for alloy additive, tungsten and its alloys are widely used in electronics, electric light source industry, also in the aerospace, casting, weapons, etc. Used in rocket nozzle, die-casting molds, armor-piercing core and contact, such as heating element and heat shield.
Tungsten was first used to make incandescent filament. In 1909, W.D.C. Coolidge used tungsten powder pressing, remelting, rotary forging and wire-drawing to make tungsten wire. Since then, tungsten wire production has developed rapidly. In 1913, after i.langmuir and w.rogers discovered that the electron emission performance of thorium filament (also known as thorium tungsten filament) was better than pure tungsten filament, thorium filament began to be used and is still widely used today. In 1922, tungsten filament with excellent anti-sag performance (known as doped tungsten filament or non-sagging tungsten filament) was developed, which was a major advance in tungsten filament research. Non - sagging tungsten filament is widely used as an excellent filament and cathode material. In the 1950s and 1960s, tungsten alloy was studied extensively, hoping to develop tungsten alloy that could work at 1930 ~ 2760℃, so as to make high-temperature components for aerospace industry. Among them, tungsten-rhenium alloy has been studied more. Tungsten ingot is obtained by consumable arc and electron beam smelting, and some products are made by extrusion and plastic processing. But the smelt ingots have coarse grain, poor plasticity, difficult processing and low yield, so smelt - plastic processing technology has not become the main means of production. Except chemical vapor deposition (CVD) and plasma spraying can produce very few products, powder metallurgy is still the main means of producing tungsten products.
