抄録
The relative density and average Cu grain size of the sintered compact which was prepared from Cu ultrafine powder (0.03 μm, 6.3 mass% oxygen) and Al2O3 powders (0.02 or 0.5μm) were investigated in relation to the relative density (Dg) of green compact and the amount and particle size of Al2O3 powder. The compacts were sintered mainly at 1273 K for 3.6 ks in hydrogen.
The fully dense sintered Cu-Al2O3 compacts were obtained in the range of a small amount of Al2O3 (the limiting value was about 4 vol% for Al2O3 of 0.02 um, and 10 vol% for Al2O3 of 0.5 μm), when Dg was below a critical value (Dgc) in the same way as in the case of the pure Cu compact. The Dgc increased with increasing amount of A12O3 powder. When the amount of Al2O3 was lager than the above limiting value, the sintered compact became porous, irrespective of Dg. The grain growth of Cu matrix became more surpressed in general as the Al2O3 powder became larger in the amount and finer in the size; the minimum average grain size in the dense Cu-Al2O3 compact was about 2 μm, compared with 9 um in the pure Cu compact.
