Hollow corundum microspheres Ni-HCM
The main feature of the use of nickel-coated hollow corundum microspheres (Ni-HCM) is their self-sharpening capability due to pore-forming agents in diamond grinding wheels, diamond tools, diamond cutting wheels and grinding stones.
The strength of a diamond grain is much higher than that of a Ni-HCM microsphere; therefore, it is the diamond grains that cut and tear the metal part, while "exposed" Ni-HCM microspheres remove metal burrs and then crumble, forming new sharp edges.
This self-sharpening effect helps to achieve the following:
- Smaller surface roughness of the processed metal in one pass of a diamond tool with 15-30% Ni-HCM.
- Improvement of the cutting properties of the abrasive tool due to the presence of Ni-HCM microspheres increases the service life of a diamond tool by 30-50%.
- Artificial porosity in diamond tools helps to reduce grinding time.
- The abrasive tool does not need resharpening, as the internal cavity of Ni-HCM and the space around it is cleaned with liquid, effectively increasing the quantity of processed metal products and prolonging the life of the abrasive tool.
- High adhesion properties of Ni-HCM when bonding to metal or plastics provide for attachment of microspheres to a diamond tool.
Properties of Ni-HCM
- Main material: theta and alpha aluminum oxide Al2O3 (corundum);
- Coating layer: nickel metal 3-25 PBW;
- Spherical shape
- Increased particle surface, cm2/cm3;
- Particle size: 5-200 µm;
- Bulk density: 1.8-2.4 g/cm3;
- Refractoriness: HCM - 1700-1800°C;
- High mechanical strength, up to 120 MPa;
- High abrasive properties;
- Excellent adhesive properties when bonding to metal and plastics.
Kit-Story SPB, 86199406 Russia, St. Petersburg, Sredniy Prospect, Vasilyevsky Island
Tel./Fax: +7(812)677-34-59 e-mail:info@t-tiss. com
Types of hollow corundum microspheres with nickel coating (Ni-HCM)
| Размер |
Микрон |
5-100 |
70-180 |
5-40 |
40-70 |
70-100 |
100-140 |
140-180 |
| Ni |
% |
3-25 |
| Al2O3 |
% |
99,6 |
| Fe2O3 |
% |
0,003 |
| CaO |
% |
0,01 |
| SiO2 |
% |
0,025 |
| Na2O |
% |
0,26 |
| LOI*, No more than |
% |
0,48 |
| a-Al2O3 |
% |
28 |
| Bulk density |
g/cm3 |
1,8-2,4 |
LOI*, % - relative mass change when baking
