| 摘要 |
PURPOSE: To obtain nonmagnetic ceramics not causing chipping at the time of mechanical working by heating a soln. contg. a complex of nitrates of Co and Ni in a specified molar ratio with an amino acid and subjecting the resultant powder to compacting, firing and HIP. CONSTITUTION: A soln. contg. a complex of nitrates of Co and Ni with an amino acid is prepd. so as to give a multiple oxide represented by the formula (where 0.15<=x<=0.9). This soln. is heated to evaporate the water and the resultant powder is granulated with a spray drier, etc., fired at <=1,250 deg.C and subjected to HIP to obtain the objective nonmagnetic ceramics having <=5μm average grain diameter and a Vickers hardness of >=650. This ceramics has a coefft. of thermal expansion almost equal to that of a head material, also has superior chipping resistance and is suitable for use as a substrate material for a magnetic head. |
