Effect of high energy ball milling and low temperature densification of plate-like alumina powder

The effects of high energy milling on the shape, size and low temperature sinterability of plate-like alumina pow-der was studied. The milling effects were studied under three different processing conditions, designed by vary-ing the charge ratio and the milling medium. 10:1 and 20:1 ball to powder charge ratios were considered in wet and dry milling media, with powder samples collected after 4, 8,16 and 32 h of milling. Analysis demonstrates that 20:1 wet milled powders underwent greatest size reduction with a final average particle size of 0.29 um and crystallite size of 10.13 nm. 20:1 wet milled powders were subsequently sintered at 1300 degrees C for 10 and 20 h. Results indicate that densification and hardness increased as a function of milling time, reaching to a max-imum for 16 h milled samples with the least amount of porosity. (c) 2021 Elsevier B.V. All rights reserved.