Processes

Vacuum Plasma Spray (also referred to as Low-Pressure Plasma Spray) combines all the advantages of plasma spray within an inert environment to produce very dense coatings with the lowest oxide content. Vacuum Plasma Spray is cost effective for the spray forming of specialized materials, refractory metals and reactive materials (e.g. titanium). Vacuum Plasma Spray offers the following advantages over conventional atmospheric plasma process:

• Broader and longer spray jets
• Cleaner interfaces through reverse transfer arc sputter cleaning
• Oxide-free coatings
• High coating densities (close to theoretical)
• Low residual stresses
• Increased deposition thickness capability (>25mm or 1 inch)
• High substrate/deposit preheating capability

Applications:

• Planar and cylindrical sputter targets
• Thermal Barrier Coatings
• Medical Device and Implant Coatings
• Refractory Metals
• Dense Ceramics
• Superalloys
• Rocket Nozzles

Shrouded Plasma Spray offers the versatility of atmospheric plasma spray within an inert atmosphere. A shroud of protective gas surrounds the plasma jet and reduces the amount of oxygen available to oxidize the material being deposited. Shrouded Plasma Spray is used for oxygen-sensitive applications where functionality, size and budget do not require vacuum plasma spray deposition.

Applications:

Oxidation-resistant coatings
Thermal barrier coatings (TBC’s)
Corrosion-resistance
Neutron absorbing materials
Medical device and implant coatings

Atmospheric Plasma SprayThe most flexible of thermal spray processes with ability to coat virtually any material while achieving excellent control of coating thickness and surface characteristics.

A strong electric arc is generated between a positively charged pole (anode) and a negatively charged pole (cathode). This ionizes the flowing process gases into the plasma state. Powdered feedstock material is injected into the plasma jet, melting the powder particles and propelling them to the surface of the workpiece.

Applications:

Oxidation-resistant coatings
Thermal barrier coatings
Corrosion-resistance
Neutron absorbing materials
Medical device and implant coatings
Wear resistant
Electircal contacts

Cold Spray is a material-deposition process whereby particles between 1 and 40 microns are impacted at high velocity onto a substrate. The particles are placed in a gas stream of nitrogen, helium or air, then heated and accelerated through a de Laval supersonic nozzle at speeds ranging from 1000 to 2500 meters per second. The particle stream is directed towards a substrate, where the particles are consolidated in the solid state.

A distinguishing feature of the cold spray process compared to conventional thermal spray processes is its ability to produce coatings in a range generally lower than the melting temperature of the coating. Consequently, deleterious effects of high-temperature oxidation, evaporation, melting, recrystallization, residual stresses, debonding, and other concerns associated with thermal spray methods with a liquification step are minimized or eliminated. Cold Spray coatings are typically limited to ductile materials like aluminum, stainless steel, copper, titanium and alloys. Hard and brittle materials like ceramics cannot be sprayed in the pure form but may be applied as composites with a ductile matrix phase. Substrate materials are also limited to those that can withstand the aggressive action of the spray particles. Soft or friable substrates will erode rather than be coated.

Applications:

Additive/3D Printing
Aerospace (MCrAlY)
Automotive; corrosion protection for automotive body and chassis structures (Al and Zn)
Chemical (Ti)
Rapid Protyotyping
Rapid Tooling Repair
Dimensional Restoration (Al, Mg, Cu, Steel)

Wire Arc SprayWire Arc Spray (also referred to as Electric Arc Spray) is a simple, fast and economical thermal spray process for in-shop or on-site work. Wire arc spray works by placing an electric arc between two consumable electrodes of a coating material, then using compressed gas to atomize and propel the material to the substrate. Wire Arc Spray occupies an important niche in thermal spray technology and is particularly suited to high-rate deposition.

Applications:

Corrosion Protection
Non-skid surfaces
Low-temperature-capability for coatings onto substrates such as polymers and paper
Erosion- and wear-resistant coatings
Dimensional restoration
Metalizing
Electromagnetic shielding