Fast pressureless solid-state reaction sintering of highly infrared transparent MgAlON ceramics from MgAl2O4 and AlON powders by two-step heating. Issue 6 (June 2023)

• Record Type: Journal Article
• Authors: Jiang, Xuan; Sun, Xiannian; Ma, Liya; Huang, Chaojun; Shan, Yingchun; Xu, Jiujun; Li, Jiangtao
• Is Part Of: Journal of the European Ceramic Society. Volume 43:Issue 6(2023)
• Page Start: 2614
• Page End: 2623
• Publication Date: 2023-06
• Subjects: Two-step heating -- MgAlON -- Solid-state reaction -- MgAl2O4 and AlON powders; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2023.01.021
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: A two-step heating strategy was proposed to fabricate transparent MgAlON ceramics by solid-state reaction of MgAl2 O4 and AlON powders via pressureless sintering. By dwelling 60 min at 1700 ℃ followed by 150 min at 1880 ℃, highly infrared transparent MgAlON ceramics with transmittance up to 80.4 % were successfully fast prepared. The phase transformation and microstructure evolution during heating from 1400 ℃ to 1800 ℃ and dwelling at 1700 ℃ for 0–90 min was thoroughly studied to reveal the solid-state reaction and densification mechanism of MgAlON by two-step heating. Surprisingly, it was found that the grown grains could break during dwelling at 1700 ℃. This secondary massive fragmentation of grown grains resulted in the minimized grain size and improved moveability of grains, which in turn prompted fast and high densification with pore free in the following sintering step. The grain breakage at 1700 ℃ could be attributed to the decomposition of AlON and formation of MgAlON.