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1326 |
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Tuesday, June 03, 2008, Room 04 1:40 PM New Equipment 3 Latest developments in thermal spray equipment, modern multiple arc plasma guns, optimized powder feeder, new vacuum processes |
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Comparison of coating stresses produced by high velocity liquid fuel and triplex pro 200 plasma guns using in-situ coating stress measurement |
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Ron Molz* / Sulzer Metco (US), USA Alfredo Valarezo/ SUNY, Stonybrook, USA Jose Colmen/ SUNY, Stonybrook, USA Sanjay Sampath/ SUNY, Stonybrook, USA |
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The coating stresses induced by thermal spray using a High Velocity Liquid Fuel (HVLF) gun and a High Velocity Plasma (HVP) gun with the high velocity nozzle are compared using a new in-situ coating stress analysis tool that measures the deflection of a beam while a coating is applied to the beam. This novel new diagnostic tool provides new insights into the internal stresses generated in a coating system during the actual application of the coating. Coatings were sprayed with both process guns and the same material feed stock that result in similar coating structures and properties. Both the HVLF and HVP processes induce similar particle energy states as measured with particle diagnostic tools during spraying but due to the differences in particle history are expected to result in different coating stresses. In some cases the actual measured stress conditions using the in-situ coating stress tool were dramatically different and theories are presented to explain the reason for these surprising results. The understanding of these differences will lead to improved methodology for mapping coating processes from one process to another along with a more in depth understanding of residual coating stresses overall. |