J0450102 SPS成形したAg/ダイヤモンド複合材料の熱物性に及ぼすダイヤモンドのバイモーダルな粒度分布の影響([JO45-01]知的材料・構造システム(1),機械材料・材料加工部門)

Abstract

Diamond-particle-dispersed-silver (Ag) matrix composites were fabricated in solid-liquid co-existent state by Spark Plasma Sintering (SPS) process from the mixture of diamond powders, Ag powders and Si powders. As the diamond powders, two kind of powders, monomodal diamond powders of 310μm in diameter and a bimodal diamond powder mixture of 310μm and 34.8μm in diameter, were used. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were all well consolidated by heating at a temperature range between 1113K and 1188K for 0.45ks during SPS process. No reaction at the interface between the diamond particle and the Ag matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. Although the relative packing density of the monomodal composite decreased from 97.4% to 93.4% with increasing the diamond volume fraction in a diamond volume fraction range between 50% and 60%, that of the bimodal composite was higher than 97% in a diamond volume fraction range up to 65%. The thermal conductivity of the bimodal composite was 576-723W/mK, which is higher than that of the monomodal composite in a diamond volume fraction range between 55% and 65%, and it is 678-723W/mK in a diamond volume fraction range between 55 and 65vol.%.