All corundum types have individual performance profiles. Various mechanisms to increase grit toughness take effect in the different corundum grits [LUDE94, p. 74 ff].
2.1.5.1 Molten Corundum
Pure white corundum is one of the hardest, but most friable corundum grit types and is used most in vitrified grinding wheels for precision grinding processes [MARI07, p. 77]. The low sodium content of pure white corundum deters tool breakdown from cooling lubricant attack [MARI07, p. 77].
Zirconium corundum undergoes a martensitic phase, which increases the toughness transformation and depends on the process load (see Sect. 2.1). This can be an advantage, but this mechanism needs a certain load level [LUDE94, p. 77].