Tungsten applications

Tungsten is widely used, the most common is tungsten&moly tungsten weights carbide 

(WC) carbide. Such carbide used in metalworking , mining , 

oil and construction industry as durable metal . In addition, 

in the tungsten filament bulbs and tubes applications are 

very wide. Tungsten is also used as an electrode . You can 

pull into a very fine tungsten wire , and a very high melting 

point . Its other applications include :

Due to a very high melting point of tungsten wire , so 

commonly used in the aerospace and high-temperature 

environments , such as electronics, heating and welding (EG 

gas tungsten arc welding ) .

Tungsten is very hard, very close , and therefore ideal 

for the production of heavy metal alloy , this alloy is used 

in the armor, heat sinks and high- density applications such 

as ballast, balance weights , boats and aircraft, ballast and 

so on .

Because tungsten is very close , darts often contain 80-

97% of tungsten.

High-speed steel with tungsten sheet , sometimes containing 18 

% tungsten .

Turbine manufacturing tablets, durable and protective 

layer portion containing tungsten superalloy ( Hastelloy , 

Stellite , etc. ) .

Using tungsten bullets instead of lead.

Tungsten compound is used as catalyst, inorganic colors. 

Tungsten disulfide is a high-temperature lubricant , it 

remained stable at 500 ° C.

Since a similar rise and tungsten borosilicate glass , so 

people carried it with glass / metal seal

Tungsten and nickel, iron and cobalt alloys are used to 

make heavy alloys , such as heavy alloys used in kinetic 

energy to replace depleted uranium bombs .

Tungsten in an integrated circuit is connected between 

the road thing . Silica insulator erosion contact hole 

injection tungsten polished to connect transistor. Typical 

contact holes as small as 65 nm.

Tungsten is one of the hardest material , was used in the 

machine tools and abrasives . Tungsten carbide is abrasive 

and turn with the most common material , and often the best 

materials .

Tungsten is in radiology shielding material . 

Transportation fluorodeoxyglucose general use tungsten 

container because fluorodeoxyglucose in high energy fluorine

-18 lead containers so can not be used .

Chemical properties of tungsten

Refractory metal tungsten&moly tungsten wire is a rare , high-temperature

hardness of the steel can be improved , the sixth period of

the periodic table are ( second long cycle) Ⅵ B family.

tungsten weights is a silvery-white metal that looks like steel.

Tungsten high melting point, low vapor pressure , evaporation

rate is also small . Tungsten is chemically stable at room

temperature when not react with air and water when not

heated, any concentration of hydrochloric acid, sulfuric

acid, nitric acid, hydrofluoric acid and aqua regia tungsten tube

are ineffective when the temperature was raised to 80 ° -100

when ° C, these various acids , except hydrofluoric acid ,

the other weak acid on the role of tungsten occur . At room

temperature , can be quickly dissolved in a mixture of

tungsten acid, hydrofluoric acid and concentrated nitric acid

, it does not work in an alkaline solution. The presence of

air under the conditions of the tungsten oxide can be melted

into the base tungstate , in the presence of an oxidant

(NaNO3, NaNO2, KClO3, PbO2) exists , the generation of a more

violent reaction tungstate . High temperature with chlorine,

bromine , iodine , carbon, nitrogen , sulfur and other

compounds , but not together with the hydrogenation .

Accelerate the oxidation of tungsten, seriously shorten the life of the product, resulting in product failure

Tungsten halogen lamp with a key piece for the electrodes, tungsten and key pieces connected by spot welding, glass bulb filled with hydrogen, platinum plate and a glass full sealing at high temperatures to form tungsten halogen lamps. Tightness after sealing a direct impact on the life of the lamp. The quality of the products examined the strange, often found in air bubbles in the glass sealing surface Swiss platinum pieces, about 20% of total production. Gas tube leak caused the emergence of satiety, while accelerating the oxidation of tungsten, severely  copper molybdenum  of the product, resulting in product failure. In order to find out the reason for the gas saturation and gas saturation of the proposed measures to prevent, paper, failure analysis methods applied spectroscopy, scanning  Tungsten copper alloy  and transmission electron microscopy and other means to conduct research on a seal platinum chip sealing in high temperature and glass. The results showed that when aluminum and glass at high temperature sealing, are key causes of the bubble sheet internal inclusions and gases, the paper also presents how to prevent bubbles.