Influence of ball milling parameters on blue phosphor for cathode ray tube

摘要

A series of experiments have been conducted to examine ball milling parameters, such as the size of beads, ball milling time, the ratio of beads/phosphor/water, and the material composition of the ball milling beads to optimize the milling conditions for phosphor powders. It is concluded that longer time, smaller size of Φ2 Al_2O_3 beads, and higher ratio of beads/phosphor/water = 2:1:0.5 can produce phosphor powder with higher dispersibility which in turn creates a densely packed coating of phosphor particles on the screen, a necessity for high resolution and high cathodoluminescence. When harder material with higher density are applied in the disagglomeration process or lower density beads which have undergone a longer ball milling time, the dispersion result is more effective. Nevertheless, the brightness of phosphor powder may deteriorate, a side effect which is undesirable for high quality phosphor powders. The concept of dispersibility is also proposed by evaluating the sediment volume, hardness, and ratio of water absorption.