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

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 Al2O3 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.