Posted by Gordon England on February 12, 2003 at 18:19:45:
In Reply to: Thermal spray coating on Turbine blades posted by sudhanshu gupta on February 12, 2003 at 13:20:58:
: We are an IPP and run our plant through 3GTs in combined cycle operation. TIT is 1060 to 1090 Deg. C.
: MCrAlY is applied on 1st and 2nd stage stationary vanes and rotating blades of the Gas Turbines.
: Lot of debate goes on, on which coating process to be applied ie whether LPPS/VPS or HVOF as widely varying experiences and practices are available thorugh out the Industry (Refurbishers and OEM including).
: 1) Could through detailed light on which proces is technically better over the other?
: 2) Some quantifiable details about commecial aspects of the these coatings?
: 3)Whether there is any difference between LPPS and VPS?
: Would await for your response.
: Regards
: Sudhanshu Gupta
: Engineering Services
: Gujarat Paguthan Energy Corporation Ltd.
: Bharuch Palej Road
: Village Paguthan
: Dist. : Bharuch, Gujarat, India
: PIN - 392015
: Tel . : +91 2642 288501; ext. : 1110
: Fax : +91 2642 288512
1. LPPS/VPS coating is probably technically better as the coatings will be diffusion bonded due to higher processing temperatures and contain less oxide. The components are usually put through a heat treatment cycle during processing. HVOF coatings one the otherhand can be applied without heat effecting the substrate metallurgy.
2. HVOF will have the advantage of being very much cheaper.
3. LPPS (low pressure plasma spraying) VPS (vacuum plasma spraying) are really the same.
Regards Gordon
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