The effect of high-energy milling on the crystallite size of alumina

The experiment aims to investigate the effect of high energy milling to the crystallite size of α-alumina. The starting material used is α-alumina powder with starting crystal size of 86 nm. This powder was milled at different time ranges from 0 to 60 minutes and milling speed ranges from 400 rpm to 1100 rpm using a wet milling technique in corundum abrasive materials. The wet milling technique involved the use of water with the alumina to water ratio of 1:6:1. samples prepared were then examined using the X-ray Diffraction (XRD) to calculate the crystallite size and scanning electron microscope (SEM) was also used to determine changes in the morphology. Results from these analysis showed that the crystallite size will get smaller when milling speed and time of more than 600 rpm and 30 minutes respectively were used. Optimum conditions to achieve the smallest crystal size of 79.7 nm are 1000 rpm and 60 minutes. (author)