Description of Process Types

Surface engineering process technologies meet specialist requirements using different metals, paints and plastics in any combination.

In general terms, surface engineering processes can classified into the following categories:

• Aqueous Electrolytic
  normally consisting of electroplating of metal coatings, anodising of aluminium and titanium, as well as the electropolishing of stainless steel.
  
• Electroless Processes
  for those metals, notably copper, nickel, gold and tin that can be applied by chemical reduction methods and avoid the use of electrolytic energy.
  
• Aqueous Non-electrolytic
  typically cleaning, pickling, phosphating, passivation, mechanical plating and a variety of other colouring processes, e.g. "blacking" of steel.
  
• Organic (Liquid)
  which can be solvent or water based but applies pigmented or metal containing coatings by dipping, dip-spinning, flow coating, conventional spraying, or in the case of water based paints, by electrophoretic or auto-catalytic means.
  
• Organic (Powder)
  the application of dry powders, usually by the process of electrostatic spraying or by fluidised bed techniques.
  
• Heat Treatment
  The use of heat and, in some cases gases, to metallurgically alter the structure and mechanical properties of a component. The component may be stress relieved, softened or hardened or even changed in composition especially where unique surface properties are desired.
  
• Galvanising
  a process where ferrous articles are dipped into molten zinc (or an alloy of zinc) to produce a relatively thick surface layer of zinc, (or zinc alloy).
  
• Tinning
  a process where ferrous articles are dipped into molten tin, (or an alloy of tin), to produce a relatively thick layer of tin, (or tin alloy).
  
• Metal Spraying
  a technique for uniquely transferring metals by the use of heat, plasma, or arc to the surfaces of prepared components.
  
• Vitreous Enamelling
  the application of metallic glass containing liquids by dipping / spraying techniques on to ferrous components.