Oxygen-filled die casting is only applicable to aluminum alloy die casting. The so-called oxygen-filled die casting refers to filling the pressure chamber and die casting mold cavity with dry oxygen to replace the air and other gases therein, so that the oxygen remaining in the cavity during the die casting process reacts with the aluminum liquid to form Al2O3 particles, thereby eliminating the pores formed inside the die casting when no oxygen is filled. This Al2O3 particle is fine, about less than lpm, and its mass accounts for 0.1%~0.2% of the total mass of the die casting, which does not affect the mechanical properties and allows the die casting to be heat treated. Oxygen-filled die casting is an effective way to eliminate pores in aluminum alloy die castings and improve the quality of die castings.

1. Characteristics of oxygenated die casting
(1) Eliminate or reduce the pores inside the die casting and improve the quality of the die casting. The strength of oxygenated aluminum alloy die castings is 10% higher than that of ordinary die castings, and the elongation is increased by 0.5 to 1 times.
(2) Oxygenated die castings can be heat treated to improve their mechanical properties. After heat treatment, the strength of the casting can be increased by more than 30%, the yield strength is increased by 100%, and the impact toughness is also significantly improved.
(3) Oxygenated die castings can work in an environment of 200~320℃.
(4) Oxygenated die-casting causes little burning loss of aluminum alloy components.
(5) Compared with vacuum die casting, oxygenated die casting has simple structure, convenient operation and less investment.

2. Applications
Oxygen-filled die casting is mainly used for aluminum alloy products, including parts that require high strength or heat resistance. Aluminum alloy parts produced by oxygen-filled die casting abroad include automobile wheels, brake cylinders, connecting rods, gear-rack steering mechanism housing intake manifolds, hydraulic transmission housings, lift door hinges, etc. In recent years, with the requirements for lightweight automobiles, magnesium alloys have begun to attract people’s attention, and the application of magnesium alloys in automobiles has increased year by year. Some foreign companies have used oxygen-filled die casting to produce magnesium alloy automobile and motorcycle wheels, and research in this area is still ongoing.