|
3845 |
|
Thursday, May 22, 2014, Hall H3 4:20 PM Arc Spraying & Laser Spraying |
|
Investigation of the effect of porosity content on the felxural behavior of nickel foam core sandwich structures with arc sprayed alloy 625 skin |
|
Saeid Salavati / Center fro Advanced Coating Technologies, University of Toronto, Canada Pakeeza Hafeez / Center for Advanced Coating Technologies, University of Toronto, Canada Larry Pershin/ Center for Advanced Coating Technologies, University of Toronto, Canada Sanjeev Chandra/ Center for Advanced Coating Technologies, University of Toronto, Canada Javad Mostaghimi/ Center for Advanced Coating Technologies, University of Toronto, Canada Thomas W. Coyle*/ Center for Advanced Coating Technologies, University of Toronto, Canada |
|
A potential application of open cell metallic foam core sandwich structures prepared by thermal spray processes is as heat shields for the protection of parts exposed to high temperature gas against hot corrosion and hot oxidation. One approach to protecting surfaces exposed to high temperature gas flows is to form a boundary layer of cooler gas along the surface, typically by allowing cool gas to flow from internal passages through a pattern of holes drilled in the surface of the component. The production of this pattern of fine holes is time consuming and expensive. In this study we have explored the feasibility of creating a cool gas boundary layer along the outer surface of a metallic foam core sandwich structure heat shield by controlling permeability of the faces of the sandwich structure. The faces were fabricated by twin wire arc spraying of alloy 625. Production of high open porosity coatings using the twin wire arc process with metallic wire feedstock is a challenge. The effects of substrate surface preparation, twin wire arc deposition parameters, and the introduction of pore forming powders to the coating were explored in attempting to increase the porosity of the deposits. |