INTRODUCTION
COLD SPRAY PROCESSBy-: Rishabh Ranjan 3143515 M.Tech (I.P).
CONTENTSHistory.Introduction.Principle.Needs.Process
ParametersCu coating.Advantages.Applications.Case
Study.Refrences.
HISTORYDr Antolli Papyrin of Russian Academy of Sciences was the
first to demonstrate the cold spray process in the
mid-1980s.[1]INTRODUCTIONCold Spraying is a material deposition
technique.Powder Particles(10-50 m) are accelerated to supersonic
gas jet velocity(350-1000m/s).He and N are used as process gases.De
Laval Nozzle is used.Plastic Deformation occurs due to Adiabatic
Shear Instabilities.PRINCIPLE [4]
NEEDSFor depositing temperature sensitive materials.For
depositing oxygen sensitive materials.Precise amount of deposition
in surface(spray beam ~5mm diameter).Corrosion Resistant Coatings
(Zn, Al).Wear Resistant Coatings (CrC-NiCr, WC-Co, WCu).
PROCESS PARAMETERS[5]Jet Pressure 1-3(Mpa).Jet Velocity
350-1000(m/s)Jet Temperature 0-700C.Gas Flow Rate
1-2(m3/min).Powder Flow Rate 2-8(Kg/h).Spray Distance
10-50mm.Particle Size 10-50 m. Expression for Critical
velocity-:[2]
Cp-Particle specific heat.Tm-Particle melting temperature.p
Particle density.TS Particle Tensile Strength.Tpi-Particle Impact
Temperature.
Cu COATING BY COLD SPRAYING[3]Cu powder (
