SPONTANEOUS INFILTRATION OF ALUMINA BY COPPER-OXYGEN ALLOYS

Infiltration of alumina powder compacts by molten copper-oxygen alloys under controlled oxygen partial pressures has been studied, Spontaneo us infiltration occurred for copper alloys containing more than approx imately 5 at.% oxygen, Despite supersaturation of the copper with oxyg en, no Cu2O or interfacial reaction layers of CuAlO2 were resolved by TEM, suggesting the critical wettability for infiltration is not deter mined by interfacial chemical reaction, CuAlO2 did form, but as discre te inclusions up to 0.5 mm in diameter. Infiltration and microstructur e development are discussed in terms of the observed wetting behavior and available data on interfacial oxygen adsorption.