Thermal spraying techniques are coating processes in which melted (or heated) materials are sprayed onto a surface. The "feedstock" (coating precursor) is heated by electrical (plasma or arc) or chemical means (combustion flame).
Thermal sprayed surface has pores. It will be covered by releasing coating and no galvanic effect.
During materials are being heated and sprayed, they are combined with oxygen and nitrogen, partly turning into oxide and nitride. So that the feature of material is changed and gets extra hardness also to improve wear resistance.
➤ Various kinds of metals can be used as thermal spray material
Metal, Alloy, Ceramics, Cermets, polymer, etc.
As thermal spray surface is thiner than cladding, it's
economical even with expensive material.
➤ On-Site application is available.
➤ It's possible to apply only to the corroded part in the structure.
- Easy to maintain thermal sprayed surface, leading to longer
life of structure
<Comparison with plating>
➤ No need to use plating bath, it's applicable even to big structure.
➤ No need for pickling, no risks of hydrogen embrittlement.
➤ Dipping plating is not suitable for topcoating, but thermal spray has good connection.
<Comparison with painting>
➤ Paintings has the risks of peeling off and blistering since coefficient of thermal expansion is different between metals and paints, that limits the use under high temperature.
➤ Thermal spray can be used high temperature over 1000°C, since coefficient of thermal expansion is closer with using metal material.