Effect of Powder Morphology on Thermal properties and strentgh of High Heat Flux Porous Coatings Synthesized by Powder Metallurgy
Subject Areas :
1 - سازمان پژوهشهای علمی و صنعتی ایران-پژوهشکده مواد پیشرفته و انرژیهای نو
2 - پژوهشکده مواد پیشرفته و انرژیهای نو - سازمان پژوهشهای علمی و صنعتی ایران
Keywords: permeability, Porosity, mechanical alloying, Copper - Nickel Powder, Sintered Porous Wicks,
Abstract :
Recently, with decreasing energy resources, it is favorable to use new materials to increase efficiency. High heat flux coating is one of the porous coatings that are created on base plate with pressure less sintering of powders. These coatings increase surface, besides increasing bubble nucleation sites and permeability. Porosity volume, deboning strength and permeability are the most important physical property of these coatings that affected by powder size and powder morphology as well as sintering conditions. In this research, the effect of powder morphology on physical properties (porosity, deboning strength and permeability) of High Heat Flux porous coatings was investigated. Spherical, dendritic and irregular powders by using a polymeric binder were created on Cu base plate in an atmospheric control furnace (H2-N2) with specified heat treatment cycle (without any pressure). Porosimetery test was carried on porous coating samples. Results for spherical, dendritic and irregular powders were 24.5, 49.5 and 58% respectively. For mentioned samples, deboning strength was, 1.4, 0.52 and 0.82 (kN). Permeability of samples was in 3.3×10-12 to 4.8×10-12 (m2) range. Results show that maximum permeability and porosity were belonged to the irregular powder with minimum strength and spherical powder with maximum strength has minimum permeability and porosity.
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