Corrosion-resistant, hard, gold-coloured ceramic article

The articles contain 0.1-30 (2-20) wt.% Al2O3 and/or ZrO2. The articles can be used as watch and clock casings, medals, bracelets, rings, buttons, wall covers or as other pieces of jewellery or decorative materials. The incorporation of Al2O3 and/or ZrO2 greatly improves the corrosion-resistance of the articles. Vickers hardness is at least 1200 kg/sq.mm and flexural strength at least 30 kg/sq.mm. The particle size of Al2O3 and/or ZrO2 is below 2 (below 1) microns. The Al2O3 and/or ZrO2 powder can be added during the prepn. of the starting material powder. The mixt. is compressed and sintered in a non-oxidising atmos., e.g. at 1600-1900 deg. C, or in vacuo, e.g. at 10 power -2 to 10 power -5 torr.