AZ25 is an electro-fused alumina zirconia grain,produced by fusing high grade alumina and zirconia at about 2000 ℃ temperature in an electric arc furnace.And then by quenching,crushing and sizing to the desired grain sizes. This alumina-zirconia(25%) grain consists of the fine primary Corundum as well as ZrO2-Al2O3 eutectic crystalline.This microstructure offers the high intrinsic grain strength and high wear resistance to dulling. AZ25 is a hard,very tough and sharp abrasive material for uses in producing large grinding wheels for foundry snagging. AZ25 grain has a very blocky shape with rounded and mulled edges,it is used mainly for producing large organic grinding wheels for steel conditioning industry.
| Items | Al2O3 | ZrO2 | TiO2 | Fe2O3 | SiO2 |
| ZA25 | 68-72 | 24-30 | ≤1.5 | ≤0.5 | ≤1.0 |
| ZA40 | 55-57 | 35-44 | ≤1.5 | ≤0.5 | ≤1.0 |
Physical Properties
| Crystal Form | Monoclinic,tetragonal system |
| Reaction with acid and alkali | no |
| Reaction with carbon | Forming carbide since 1650C |
| Color | Grey |
| True Density | 4.20g/cm3 |
| Bulk Density | 2.18g/cm3 |
| Moh’s hardness | 9.0 |
| Knoop hardness | 1450-2000kg/cm2 |
| Melting point | 1900C |
| Maximum service temperature | 1700C |
| Specific heat capacity(cal/g.C) | 0.2205(50-500C) |
| Heat conductivity | 0.2718 cal/cm2.sec.C |
| Linear expansivity(X10-6) | 6.82(100-700C) |
