The advantage of Zirconia Alumina for rail grinding wheel
Grinding wheels for grinding railway rails have special technical requirements. High wear resistance, grinding wheel strength, and reduced grinding wheel replacement frequency are the main demands of rail grinding wheels. This requires the selected abrasives to have higher wear resistance and toughness than ordinary grinding wheels. Zirconia alumina abrasives F12, F14, and F16 are the preferred grinding materials for this field.
First of all, the toughness of zirconia aluminum oxide is due to other fused corundum abrasives. Zirconia corundum cools quickly after fusion, and the crystals crystallize quickly, with a grain size of about 10-12um. This means that grinding self-loss of zirconia alumina is very small and the wear resistance is very high. Because zirconia alumina has excellent wear resistance, it can withstand long-term friction and wear. Thereby extending the service life of the grinding wheel. This is especially important for rails that require frequent grinding operations. It can significantly reduce the frequency of replacing grinding wheels and improve work efficiency.
Secondly, although the hardness of zirconia corundum is not as good as other fused aluminum oxide (such as white fused alumina, brown fused alumina, single crystal alumina, semi-brittle alumina, pink fused alumina), the Knoop hardness is HK 1450-1700. But it is enough to grind rails made of high manganese steel. At the same time, the relative toughness of Alumina Zirconia is about 50%, and it has good particle ductility. The toughness is much higher than the other alumina abrasives mentioned above. It can withstand long-term grinding without breaking.
Thirdly, zirconia alumina grain has good thermal stability. Zirconium alumina has a small thermal expansion coefficient and can withstand high temperature environment without deformation or cracking. During the rail grinding process, the heat generated by friction is high, but the Alumina Zirconia grinding wheel can remain stable to ensure the accuracy and efficiency of grinding.
In summary, zirconia alumina(AZ25 and AZ40) as the raw material of rail grinding wheel has irreplaceable advantages over other abrasive grits. These advantages make it widely used and recognized in the field of rail grinding.
