The difference of Arc spray and wire Flame spray
The theory of spraying
Arc spraying uses electric arcs heated between two successive wires to melt the metal, then atomize the molten metal with a high-speed air stream, according to the compressed air to atomize particles and spraying into the work-piece to form the protection coatings of thermal spray. The flame spray uses flame as the heating source, heated the metal and non-metal materials on the molten state, then it becomes the fog flow with the driven of high speed air, finally spring into the substrate. The small molten particles hit the matrix, which produce plastic deformation, to become a flake overlay deposition coating. The process is called flame spraying.
According to heat sources of burning and electric heating method, flame spray includes burning flame spraying, explosive spraying and high-speed flame spraying (HVOF); electric heating includes arc spraying and plasma spraying (also normal pressure plasma spraying, low pressure plasma spraying and water stable plasma spraying). Because arc spraying has two wires for melting, in order to avoid the difficulty of thick wire melting, then the normal size of Arc spraying wire is usually 1.6mm or 2.0mm. And normal size of wire flame spray are 2.3mm, 3.17mm or 4.76mm.
The difference of arc thermal spray coatings and flame spraying coatings:
Arc spray coatings have higher bonding strength, good coating quality, high spraying efficiency, high energy efficiency, better economic efficiency, simple operation and easy out operation etc. And the flame spraying isn’t limited to the substrate shape and size. Also wire flame spraying can use more thermal spray materials, such as metals, alloys, ceramics and composite materials etc. And these materials can make the coatings with differently properties, such as anti-corrosion, wear resistance, high temperature resistance and heat insulation. And the porous organization of flame spray coatings have the oil lubrication and anti-friction performance. The flame spray coatings macroscopic hardness can be up to 450HRB by containing hard phrase, the spray coating can reach to 65HRC. The flame spraying coating has less influence to the substrate, because the temperature of substrate surface is 200-250 degrees, and its overall temperature is 70-80 degrees, so the matrix was less changed, and the organization of materials won’t be changed too.
