| 摘要 |
PURPOSE:To obtain the title abrasive grain with the same level of strength and hardness as or higher than those of the conventional abrasive grain, excel lent grinding resistance and wear characteristics and exhibiting a self-blading property by incorporating Li2O in Al2O3 and making the crystalline structure of alpha-Al2O3 uniform and fine. CONSTITUTION:Alumina monohydrate, a lithium precursor, pref. 0.03-0.15wt.% (in terms of Li2O) water-soluble LiNO3 or LiCl, an acid such as nitric, hydrochlo ric or acetic acid (in such an amt. as to attain a pH of the dispersion of 2-4) as a deflocculant and, if necessary, an alumina particle growth inhibitor, and a water-soluble compd. of Mg, Co, Ni, Cr, Fe, Si, Zn, Mn, Ti, Zr, etc., as a toughness-improving agent are added in water and mixed at 40-80 deg.C. An alumina dispersion obtd. by performing an ultrasonic vibration treatment of this mixture is baked at 1,100-1,500 deg.C for 10min to 2hr to obtain a sintered alumina abrasive grain with a degree of crystallization of alpha-alumina of 75-95%, an Al2O3 content of 98wt.% or higher, an Li2O content of 0.01-5wt.%, a particle diameter of the alumina crystal of 1mum or smaller, pref. 0.1-0.5mum. |
