Highly wear resistant Al2O3 grinding balls of highest purity

Topic

Wear resistent transparent corundum balls.

Highly pure microstructure of sintered α-Al2O3 grinding balls. Average grain size 0.41 µm at relative density > 99.9 %. Vickers hardness HV10 = 2090 ± 50

Perfect sub-µm micostructures reduce the wear of grinding balls in volume, particle size, and impurity content

Known grinding balls with low and sub-µm wear consist, e.g. of ZrO­2 (detrimental in Al2O3 substrates for microelectronics or in alumina with high permeability for microwaves), balls of 85 % Al2O3 introduce silica impurities. Commercial high-purity Al2O3 grinding balls exhibit increased and coarser wear. The corundum balls developed here by IKTS Dresden avoid these disadvantages and enable highly pure ceramic processing for special use.


Advantages
 

  • Highest purity > 99.9 % α-Al2O3.
  • Minimum wear (1/4 of the typical wear of 85 % Al2O3 balls) due to sub-µm grain size < 0.5 µm at high relative density > 99.9%.
  • High hardness HV10 > 2000.
  • Small average particle size of wear (0.6 µm).
  • Use in fast attrition mills enabled by high specific fracture stress (750 – 1000 MPa in compression).


Services offered
 

  • License on know how. Upscaling. Contributions to the development of an industrial production of new grinding balls.
  • Supply of new wear resistant corundum balls.
  • Investigations of the performance in technical applications.
Grade of grinding balls Wear rate* [%/h]
New product from IKTS 0.025
commercial 85% Al2O3 0.09
commercial ZrO2(TZ-3Y) 0.02

* Wear of new sub-µm alumina grinding balls in an attrition mill (water, 1000 rev/min) in comparison with commercial grades.