Abrasive grains based on zirconia alumina
Disclosed herein are abrasive grains based on zirconia alumina melted in an electric arc furnace, comprising a content of 52 to 62 wt % Al 2 0 3 and 35 to 45 wt % ZrO 2 , wherein the high-temperature phases of the zirconia are stabilized by a combination of reduced Ti compounds and yttrium oxide.
1. Abrasive grains based on Al 2 O 3 and ZrO 2 melted in an electric arc furnace, having a weight content of:
Al 2 O 3 between 52 and 62% by weight,
ZrO 2 between 35 and 45% by weight, with at least 70% by weight of the ZrO 2 , based on the total weight content of ZrO 2 , being present in the tetragonal and cubic high-temperature modifications,
titanium compounds in reduced form, in particular in the form of oxides and/or suboxides and/or carbides and/or oxycarbides and/or oxycarbon nitrides and/or silicides, between 1 and 5% by weight, expressed as TiO 2 ,
Y 2 O 3 between 0.5 and 3.0% by weight,
Si compounds between 0.2 and 0.7% by weight, expressed as SiO 2 ,
total carbon between 0.03 and 0.5% by weight, and
raw-material-based impurities of less than 3.0% by weight,
characterized in that the weight ratio of TiO 2 to Y 2 O 3 is in the range of 1:2 to 5:1.
2. The abrasive grains according to claim 1 , characterized in that the weight content of titanium compounds, expressed as TiO 2 , is 1.5% by weight to 4.0% by weight and the weight content of Y 2 O 3 is 0.5% by weight to 2.0% by weight, based in each case on the weight of the finished abrasive grain.
3. The abrasive grains according to claim 1 , characterized in that the weight content of titanium compounds, expressed as TiO 2 , together with the weight content of Y 2 O 3 is between 2.0 and 6.0% by weight, based on the weight of the finished abrasive grain.
4. The abrasive grains according to claim 1 , characterized in that the weight ratio of TiO 2 : Y 2 O 3 is in the range of 2:1 to 4:1.
5. The abrasive grains according to claim 1 , characterized in that in the abrasive grains more than 20% by weight of the zirconium oxide is present in the cubic high-temperature phase and more than 50% by weight of the zirconium oxide is present in the tetragonal high-temperature phase, based in each case on the total weight content of zirconium oxide.
6. The abrasive grains according to claim 2 , characterized in that the weight content of titanium compounds, expressed as TiO 2 , together with the weight content of Y 2 O 3 is between 2.0 and 6.0% by weight, based on the weight of the finished abrasive grain.
7. The abrasive grains according to claim 2 , characterized in that the weight ratio of TiO 2 : Y 2 O 3 is in the range of 2:1 to 4:1.
8. The abrasive grains according to claim 3 , characterized in that the weight ratio of TiO 2 : Y 2 O 3 is in the range of 2:1 to 4:1.
9. The abrasive grains according to claim 2 , characterized in that in the abrasive grains more than 20% by weight of the zirconium oxide is present in the cubic high-temperature phase and more than 50% by weight of the zirconium oxide is present in the tetragonal high-temperature phase, based in each case on the total weight content of zirconium oxide.
10. The abrasive grains according to claim 3 , characterized in that in the abrasive grains more than 20% by weight of the zirconium oxide is present in the cubic high-temperature phase and more than 50% by weight of the zirconium oxide is present in the tetragonal high-temperature phase, based in each case on the total weight content of zirconium oxide.
11. The abrasive grains according to claim 4 , characterized in that in the abrasive grains more than 20% by weight of the zirconium oxide is present in the cubic high-temperature phase and more than 50% by weight of the zirconium oxide is present in the tetragonal high-temperature phase, based in each case on the total weight content of zirconium oxide.