Preparation of fine powders of a Cu-Al₂O₃ dispersion strengthened alloy has been tried by means of "Freeze-Drying Processing" (F.D.P.). Fine mixed powders of Cu-and Al-sulfates produced by F.D.P. were oxidized by heating up to 1000°C for 5 min and then reduced by hydrogen gas at 550°C for 2 hr, finally objective fine powders of a Cu-1.5 at% Al₂O₃ alloy being obtained. This alloy powder was further densified by hot isostatic pressing (H.I.P.).
In addition to several tests such as thermal gravimetry, differential thermal analysis and X-ray diffraction, scanning electron microscopy was applied to observe the structure of the sulfate powders obtained by F.D.P., the alloy powders obtained after the reduction of oxides and a high density alloy obtained by H.I.P.
A comparison of some basic powder properties such as particle size, particle shape, size distribution, etc among three kinds of Cu-Al₂O₃ powders obtained by freeze-drying process from aqueous solution, co-preci-pitation method and freezing process from molten salts was carried out and relative characters of these powders have been understood somewhat clearly.