What is tungsten hexafluoride used for?
What is tungsten hexafluoride used for?
Tungsten hexafluoride is a colorless, toxic and corrosive gas with a density of about 13 g/L, which is about 11 times the density of air and one of the densest gases. In the semiconductor industry, tungsten hexafluoride is mainly used in the chemical vapor deposition (CVD) process to deposit tungsten metal. The deposited tungsten film can be used as the interconnection line of through holes and contact holes, and has the characteristics of low resistance and high melting point. Tungsten hexafluoride is also used in chemical etching, plasma etching and other processes.
What is the densest non-toxic gas?
The densest non-toxic gas is argon (Ar) with a density of 1.7845 g/L. Argon is an inert gas, colorless and odorless, and does not easily react with other substances. Argon gas is mainly used in gas protection, metal welding, metal cutting, laser and other fields.
Is tungsten stronger than titanium?
Tungsten and titanium are both metallic elements with high melting points and strength. The melting point of tungsten is 3422°C and the strength is 500 MPa, while the melting point of titanium is 1668°C and the strength is 434 MPa. Therefore, tungsten is stronger than titanium.
How toxic is tungsten hexafluoride?
Tungsten hexafluoride is a highly toxic gas that can cause serious damage to the human body if inhaled. The LD50 of tungsten hexafluoride is 5.6 mg/kg, that is, inhalation of 5.6 mg of tungsten hexafluoride per kilogram of body weight will result in a 50% mortality rate. Tungsten hexafluoride can irritate the respiratory tract, causing symptoms such as cough, chest tightness, and dyspnea. Severe cases can lead to pulmonary edema, respiratory failure and even death.
Will tungsten rust?
Tungsten will not rust. Tungsten is an inert metal that does not react easily with oxygen in the air. Therefore, tungsten will not rust at normal temperature.
Can acid corrode tungsten?
Acids can corrode tungsten, but at a slower rate. Strong acids such as concentrated sulfuric acid and concentrated hydrochloric acid can corrode tungsten, but it takes a long time. Weak acids such as dilute sulfuric acid and dilute hydrochloric acid have a weak corrosion effect on tungsten.
