| 摘要 |
PURPOSE:To obtain spherical corundum particles having low grinding and abrading power of the particle without lowering the characteristic thermal conductivity, electrical insulation, hardness, etc., of corundum particle and suitable for electric parts. CONSTITUTION:The objective spherical corundum particle has a single particle maximum diameter of <=1507mum, an average particle diameter of 5-35mum and an alpha-ray emission rate of <=0.01c/cm<2>.hr and free from cutting edge. |
