Metal powder coatings are introduced, and spray powder occupies an important position in the entire thermal spraying material. This includes nickel based, iron-based, and cobalt based alloy powders, which can be used for repairing and maintaining mechanical parts according to different coating hardness. There are no restrictions on the substrates that can be metal or non-metal, and can be sprayed on various substrates. Spray powder coatings are commonly used in thermal spraying technology for spraying almost all solid engineering materials, such as hard alloys, ceramics, metals, graphite, etc. During the spraying process, the temperature rise of the substrate is very small, so there is no stress or deformation.