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

• Published in: Powder technology 2021-05, Vol.383, p.84-92
• Main Authors: Saghir, Maryam, Umer, Malik Adeel, Ahmed, Ashfaq, Monir, Nasbah Bint, Manzoor, Umair, Razzaq, Abdul, Xian, Luo, Mohammad, Khwaja, Shahid, Muhammad, Park, Young-Kwon
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Ball milling; Crystallite size; Crystallites; Crystals; Densification; Hardness; High-energy ball milling; Low temperature; Mechanical alloying; Morphology; Particle size; Porosity; Powder; Sinterability; Sintering; Sintering (powder metallurgy); Size reduction
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2021.01.026

The effects of high energy milling on the shape, size and low temperature sinterability of plate-like alumina powder was studied. The milling effects were studied under three different processing conditions, designed by varying 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 °C for 10 and 20 h. Results indicate that densification and hardness increased as a function of milling time, reaching to a maximum for 16 h milled samples with the least amount of porosity. [Display omitted] •Low temperature sinterability of plate-like alumina powder was investigated•The effect was studied for three process conditions by varying the ball to powder ratio•Wet and dry milling of powders was performed taking BPRs of 10:1 and 20:1 value•Wet powder milling using a 20:1 BPR was found to be the most effective condition•Wet milling for16 h resulted in optimal densification and highest hardness value