Metal 3D printing technology, as the most preface and most potential technology in the whole 3D printing technology, is an important development direction of today's manufacturing technology. Metal 3D printing equipment usually has a closed reaction chamber, which can prevent some toxic and harmful by-products from leaking after filling with inert gas, and prevent the metal powder from oxidizing at the high temperature of the laser, reducing the strength and ductility of the printed object.

Nitrogen is an economical, readily available and chemically stable gas that is key to gas solutions in metal 3D printing. Metal 3D printing equipment usually requires a sealed reaction chamber, which can prevent the leakage of toxic and harmful by-products, and eliminate the effect of the presence of oxygen on the material, and the injection of nitrogen can meet this need. Filled into the sealed chamber, play a gas circulation role, some materials have anaerobic, sufficient nitrogen can play a protective role.