Abstract: Nanocrystalline sintered bodies, and a method of making same, said sintered bodies based on a 95 to 100% content of alpha-aluminum oxide by weight, a Vickers hardness greater than or equal to 17.5 GPa, and a crystal structure where the average primary crystal size of the alpha-aluminum oxide is less than or equal to 100 nanometers.

Abstract: The invention relates to a method for the production of a sintered, microcrystalline ?-Al2O3-based shaped body, which are used, for example, as abrasive bodies, wherein an ?-Al2O3 powder is used as starting material, said powder having an average particle diameter of <2 ?m, and processed with at least one binder and a solvent with the purpose of obtaining an extrudable material that is subsequently extruded. The extrudate is then further processed into a shaped body that is sintered at a temperature range of between 1300° C. and 1750° C.

Abstract: An Al2O3 and ZrO2 based abrasive grain containing titanium compounds in a reduced form, especially in the form of oxides and/or suboxides and/or carbides and/or oxycarbides and/or oxycarbonitrides and/or silicides, corresponding to a proportion of 0.510 wt %, expressed as TiO2, containing 20-50 wt % ZrO2, wherein more than 75 wt. % of the ZrO2 is present in a tetragonal crystal form, having an overall carbon content of 0.03-0.5 wt. %, a proportion of impurities caused by raw materials of less than 3.0 wt %, wherein the rare earth content calculated in the form of oxides is less than 0.1 wt %, having an Si-compound content of 0.05-1.0 wt %, expressed as SiO2, and an Al2O3 content of 50-80 wt.

Abstract: An Al2O3 and ZrO2 based abrasive grain containing titanium compounds in a reduced form, especially in the form of oxides and/or suboxides and/or carbides and/or oxycarbides and/or oxycarbonitrides and/or suicides, corresponding to a proportion of 0.510 wt. %, expressed as TiO2, containing 20–50 wt. % ZrO2, wherein more than 75 wt. % of the ZrO2 is present in a tetragonal crystal form, having an overall carbon content of 0.03–0.5 wt. %, a proportion of impurities caused by raw materials of less than 3.0 wt. %, wherein the rare earth content calculated in the form of oxides is less than 0.1 wt. %, having an Si-compound content of 0.05–1.0 wt. %, expressed as SiO2, and an Al2O3 content of 50–80 wt.

Abstract: An Al2O3 and ZrO2 based abrasive grain containing titanium compounds in a reduced form, especially in the form of oxides and/or suboxides and/or carbides and/or oxycarbides and/or oxycarbonitrides and/or suicides, corresponding to a proportion of 0.510 wt. %, expressed as TiO2, containing 20-50 wt. % ZrO2, wherein more than 75 wt. % of the ZrO2 is present in a tetragonal crystal form, having an overall carbon content of 0.03-0.5 wt. %, a proportion of impurities caused by raw materials of less than 3.0 wt. %, wherein the rare earth content calculated in the form of oxides is less than 0.1 wt. %, having an Si-compound content of 0.05-1.0 wt. %, expressed as SiO2, and an Al2O3 content of 50-80 wt.

Abstract: The invention relates to a method for the production of a sintered, microcrystalline &agr;-Al2O3-based shaped body, which are used, for example, as abrasive bodies, wherein an &agr;-Al2O3 powder is used as starting material, said powder having an average particle diameter of <2 &mgr;m, and processed with at least one binder and a solvent with the purpose of obtaining an extrudable material that is subsequently extruded. The extrudate is then further processed into a shaped body that is sintered at a temperature range of between 1300° C. and 1750° C.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as its use.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as use.