Hot Corrosion and Its Protection with Cold Spray Coatings

Hot corrosion is very serious problem and generally observed in hot sections of boilers, gas turbines, coal gasification plants, diesel engines and incinerators. Engineers and researchers have given more intension to this phenomenon when a very severe corrosion was observed in the gas turbine engines of military aircrafts during the Vietnam conflict.The power plant industry is severely facing the problem of hot corrosion which results in the significant loss of efficiency. The efficiency of a power plant depends upon the steam temperature and the steam temperature is limited due to the hot corrosion. The powers plants are running at low efficiency all over the world due the hot corrosion problem.A number of coating techniques are available such as pack cementation, physical vapour deposition and chemical vapor deposition etc. Amongest all the coating techniques, the thermal spraying is becoming a center of attraction due to relatively simplicity of technique, cost effectiveness, and outstanding corrosion and wear protection properties. Amongest thermal spray coatings, cold spray is an promising technology which avoids various limitations of other thermal spray proces.