Argon is the most abundant, and least expensive, truly inert gas. It is used where a completely non-reactive gas is needed.
Pure argon, and argon mixed with various other gases, is used as a shield gas in TIG welding ("tungsten inert gas" or gas tungsten arc welding) which uses a non-consumable tungsten electrode, and in MIG ("metal inert gas", also called gas metal arc welding, or wire feed welding) which employs a consumable wire feed electrode. The function of the shielding gas is to protect the electrode and the weld pool against the oxidizing effect of air. Pure argon is often used with aluminum. A mixture of argon and carbon dioxide is often used for MIG welding of ordinary structural steel.
Plasma-arc cutting and plasma-arc welding employ plasma gas (argon and hydrogen) to provide a very high temperature when used with a special torch.
Metals Manufacturing Uses for Argon:
When steel is made in a converter, oxygen and argon are blown into the molten metal. The addition of argon reduces chromium losses and the desired carbon content is achieved at a lower temperature.
Argon is used as a blowing gas during manufacture of higher quality steels to avoid the formation of nitrides.
Argon is also used as a shield gas in casting and stirring of ladles.
Argon is used in aluminum manufacture to aid degasification and to remove dissolved hydrogen and particulates from molten aluminum.
Argon is used as an inert gas in the manufacture of titanium to avoid oxidation and reaction with nitrogen (titanium is the only metal that will burn in a 100% nitrogen atmosphere).
Argon is used in the manufacture of zirconium.
Manufacturing and Construction Uses for Argon:
Argon is used as a filler gas in fluorescent and incandescent light bulbs. This excludes oxygen and other reactive gases and reduces the evaporation rate (sublimation rate) of the tungsten filament, thereby permitting higher filament temperature. Most common of the mixtures is 93% argon and 7% nitrogen at a pressure of 70 kPa (10.15 psig).
It is used as a filler gas between the glass panels of high-efficiency thermo pane windows, as it is not only dry and colorless, but a relatively heavy gas that minimizes heat transmission between panels by decreasing the speed of convective movement of the filler gas between the glass panels in the window.
Electronics Uses:
Argon is used with methane as a filler gas, and as a high purity inert shield gas in the manufacture of silicone and germanium crystals used in the semiconductor industry.
Food and Beverages Uses:
Argon is used in winemaking to displace oxygen in barrels and thus prevent the formation of vinegar. Similarly, it is used in restaurant, bar and home wine dispensing units to allow storage of opened bottles without degradation of the contents.
Health Care Uses:
Argon is used to perform precise cryosurgery, which is the use of extreme cold, to selectively destroy small areas of diseased or abnormal tissue, in particular on the skin. Very cold argon is created at the site by controlled expansion of argon gas, and directed to the treatment point using a cryoneedle. This provides better control of the process than earlier techniques employing liquid nitrogen. A similar technique, cryoablation, is used to treat heart arrhythmia by destroying cells which interfere with the normal distribution of electrical impulses.
Miscellaneous Uses:
Argon is used to provide a protective atmosphere for old documents to prevent their degradation in storage and while on display.
