Effects of pressing on the thermal properties of Al-SiCp composites fabricated by plasma spraying
K. Euh, S.B. Kang
MATERIALS FORUM
ABSTRACT:Aluminum matrix composites reinforced by SiC particulates (Al-SiCp) were fabricated by the atmospheric plasma spraying. Aluminum and SiC powders were ball-milled for plasma spraying feedstock. The feedstock was deposited into freestanding bulk composite on a graphite substrate, and then the spray-formed composites were hot-pressed. The microstructural characteristics of the as-sprayed and hot-pressed composites were investigated. The effects of pressing conditions on the thermal properties of composites were discussed. As-sprayed composites had a great amount of porosity, which reduced thermal properties, especially in thermal conductivity. By pressing process, the amount of porosity decreased and consequently thermal conductivity increased. Coefficients of thermal expansion (CTEs) of the composites were affected less significantly by pressing.
Key words:feedstock; SiC particles; PLASMA SPRAYING; freestanding; pressing conditions; CTEs
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