WHAT IS COLD SPRAY?
The Cold Spray Process: Cold spray, Gas dynamic cold spray, supersonic particle deposition, is a high-energy solid-state coating and powder consolidation process. In Cold spray a high-pressure heated carrier gas, (nitrogen or helium) accelerates a metal powder through a supersonic nozzle. The powder forms a coating (surface engineering) or free-standing component (Additive Manufacturing).
Bonding mechanism: Cold spray bonding is a combination of mechanical interlocking and metallurgical bonding from re-crystallization at high strained particle interfaces.
Compared with conventional thermal spray processes, cold spray has advantages:
- metal powder sprayed is not fused or melted. The effect of heat on the coating and the substrate material is very low.
- The high kinetic energy of the metal powder sprayed and the high degree of the metal powder deformation on impact with the substrate produces a homogenous and dense coating.
- The range of coating thicknesses varies from 100 micron up to 5 centimeters or more.
- Metal coatings have the same physical and chemical properties as the properties of the base material.
Cold Spray can create mixtures of metallic / nonmetallic materials to form a coating or free-standing structure.
Some Cold Spray Applications:
- Corrosion-resistant coatings (zinc and aluminum),
- Dimensional restoration and repair (nickel, stainless steel, titanium, and aluminum),
- Wear-resistant coatings (chromium carbide – nickel chromium, tungsten carbide – cobalt, and tungsten copper),
- Electromagnetic interference (EMI) shielding of components and structures,
- High strength dissimilar material coatings for unique manufacturing solutions
- Field repair of components and systems.
Cold spray Research, Production, integration, choose from one of our 3 models of high-pressure cold spray
Characteristics of Cold Spray
Cold spray is an efficient method for the application of Metals, Metal Alloys, and Metal blends for numerous applications:
- Extremely low heat input
- Structural and mechanical properties of parent metal
- No real limit on deposition thickness
- High deposit efficiency typically > 80%
- Bond strengths > 10 ksi
- Coating Strengths > 40 ksi
- Porosity commonly below 1%
- Powder microstructure and properties are preserved
- No oxide formation,
- No alloy decomposition,
- No carbon, or combustion product entrapment
- Compressive residual stresses in coating