2001 Volume 14 Issue 1-2 Pages 13-19
Starting raw materials prepared by a thermal decomposition of a mixture obtained from aqueous solutions of Mn, Co, Ni nitrates, were ground under dry (in air) and wet (in water and alcohol) conditions by a tumbling ball mill to investigate sinterability and characteristics of NTC thermistor. The dry grinding causes aggregation of fine particles even in early stage of grinding, while the wet grinding reduces the particle size of the product. The sintered bodies from the products ground in wet using water possess large cracks, while they are fairly free from the defects when the mixture was ground in alcohol. Wet grinding in methanol with high (μ/V) value is more advantageous for producting dry fine particles, resulting in the improvement in characteristics of NTC thermistor with high density.
