We work with the following processes:

• High Velocity Oxy-Fuel (HVOF)
• Electric-arc spraying (EASP) with wire
• Flame spraying (FLSP) with wire or powder

• The layers of electric-arc process are characterized by an outstanding adhesion, yet not reached in the flame spraying. The spraying particles weld with the basic material.
• Excellent for applications that require heavy coating build-up or for large surfaces. Arbitrarily strong layers from 0.2mm to 20mm can be laid on.
• Can be sprayed at extremely high rates of speed.
• The sprayed coatings can hardly be differentiated by colour from the basic material.
• Good machinability of the oxide-poor sprayed coatings.
• Electric-arc sprayed coatings have approximately 3 times higher strength and smaller contraction strain than flaming sprayed coatings.
• Metal sprayed coatings are micro porous, which has big advantages for sliding bearings and Simmerring seats.
• You can adjust coating characteristics, such as coating hardness or surface texture.
• Independent of the basic material can all materials be coated e.g. 13% chromium steel on aluminium

Coating quality is usually assessed by measuring its porosity, oxide content, macro and microhardness, bond strength and surface roughness. Generally the coating quality increases with increasing particle velocities. The materials to be deposited as the coating are typically fed into the spray gun in powder or wire form where they may be atomized before being accelerated towards the substrate. As the sprayed particles impinge upon the surface, they cool and build up, splat by splat, into a laminar structure forming the thermal spray coating.

Most thermal spray coatings are applied directly to the substrate. If the coating is not self-bonding, the surface is first grit-blasted. If the coating is a one-step combination self-bond and build-up coating, then it can be applied over a smooth, clean surface.

Proper surface preparation of the substrate is a critical factor which influences bond strength of the coating. Other factors enhancing bond strength include the type of material being sprayed, the particle size, particle impact velocity, particle temperature, substrate roughness, and substrate surface temperature before, during, and after spraying.

Surface preparation serves two purposes. It removes any contaminants which would interfere with proper bonding of the thermal spray coating and provides a roughened surface which enhances thermal spray coating adhesion.