Thermal spraying is used for new production as well as repair and maintenance. With repair and maintenance, the method often affords cost advantages compared with buying newly-made parts. Moreover, it is not unusual for the renovated part to have an increased lifespan which means that the intervals between preventive maintenance can be extended.
Thermal spraying is the collective expression for several different spraying methods, one of which is flame spraying. When spraying equipment, the additive material, which can be in the form of powder, wire or sticks, is heated to smelting point or a practically smelted condition. The heated material is finely powdered and sprayed by means of a gas flow towards the surface of the piece (the substrate) where it fastens and stiffens. The surface cover can be used as is or worked to the correct dimensions.
It is often a component’s surface that limits its lifespan. It is the surface that is exposed to wear, corrosion and/or high temperatures. There are materials and thermal spraying methods for practically every surface quality.
Flame spraying with the correct additive material can improve the surface’s resistance to corrosion, wear and high temperatures. You can achieve surfaces with high or low friction or alter the surface’s conductivity. Damaged surfaces can be repaired and faulty parts can be corrected to the right dimensions.
The choice of fuel gas depends on the smelting temperature of the additive material and the type of spraying equipment used. For spraying polymers, it may be sufficient to use propane mixed with compressed air in order to achieve a sufficiently high temperature. For the highest temperature, acetylene mixed with pure oxygen should be used.
