Flame Powder Spray

Powder flame spraying is a thermal spraying method that uses an oxy-acetylene flame as the heat source and powder as the sprayed material.

Principle:
Powder flame spraying is carried out using a powder flame spray gun. The gun introduces oxygen and acetylene through a venturi nozzle, where the two gases mix and create a combustion flame at the nozzle exit. The gun is equipped with a powder hopper or powder inlet, and a negative pressure generated by the airflow sucks powder from the hopper. The powder is then ejected through the nozzle into the flame, where it is heated or softened, and the flame stream propels the molten particles at a certain speed to the workpiece surface to form a coating.

Coating and Process Technology Characteristics:
1. Coating Structure Characteristics:
The oxy-acetylene flame powder spray coating has a layered structure, containing oxides, porosity, and a small amount of insufficiently deformed particles. The bonding between the coating and the substrate is mechanical, and the porosity and bonding strength of the coating are significantly affected by the spraying material and process.

2. Process Technology Characteristics:
Oxy-acetylene flame powder spraying is one of the most commonly used spraying processes, with the following characteristics:
(1) Simple equipment, easy operation, low cost, and convenient on-site construction.
(2) Simple spraying process, easy to master, and widely applied.
(3) A wide range of spraying materials, including metals, alloys, composite powders, ceramics, and more.
(4) Relatively high coating porosity, low residual stress in the coating, and the ability to spray thick coatings.