| 摘要 |
<p>An abrasive grain consisting of a crystal grain of alpha -corundum the crystal size of which is substantially not more than 0.5 mu m and containing at least one of the elements Ti, Mn, V, Ga, Zn and Rh solid-solved therein, characterized in that a value of measurement of the length of a-axis of a hexagonal unit cell of alpha -Al2O3 determined by the X-ray diffraction of powder of this grain is 4.75892-4.76340 ANGSTROM with the density thereof not less than 90 % of a theoretical value, and an abrasive grain consisting of a crystal grain of alpha -corundum the crystal size of which is substantially not more than 0.5 mu m and containing at least one of the elements Mg, Ni and Co solid-solved therein, characterized in that a value of measurement of the length of a-axis of a hexagonal unit cell of alpha -Al2O3 determined by the X-ray diffraction of powder of this grain is 4.75930-4.76340 ANGSTROM with the density thereof not less than 90 % of a theoretical value; and a grindstone and abrasive cloth and paper produced by using these abrasive grains.</p> |
