Das Zustandsdiagramm des Systems Aluminiumoxyd/Wasser

Hydrothermal Synthesis of Alpha Alumina (α‐Al2O3) Powders: Study of the Processing Variables and Growth Mechanisms

“…The hydrothermal phase relationships in the Al 2 O 3 –H 2 O system, summarized in the phase diagram of Fig. 1, were established for the first time by Laubengayer and Weisz, 17 and were subsequently studied in several other investigations 18–23 . The works of Ervin and Osborn 18 and Kennedy 21,22 are consistent with the original studies of Laubengayer and Weisz and reveal the presence of only four phases, such as gibbsite, boehmite, diaspore, and corundum, in the temperature/pressure range of 0°–500°C/1–100 MPa.…”

“…1, were established for the first time by Laubengayer and Weisz, 17 and were subsequently studied in several other investigations. [18][19][20][21][22][23] The works of Ervin and Osborn 18 and Kennedy 21,22 are consistent with the original studies of Laubengayer and Weisz and reveal the presence of only four phases, such as gibbsite, boehmite, diaspore, and corundum, in the temperature/pressure range of 01-5001C/1-100 MPa. Such phase assemblage was confirmed in many experimental studies on hydrothermal synthesis of aluminas under hydrothermal conditions 6,7,[14][15][16][24][25][26][27][28][29][30][31][32] and is also cited in encyclopedic works.…”

“…Such phase assemblage was confirmed in many experimental studies on hydrothermal synthesis of aluminas under hydrothermal conditions 6,7,[14][15][16][24][25][26][27][28][29][30][31][32] and is also cited in encyclopedic works. 3 However, the works of Torkar and colleagues 19,20,23 surprisingly report the presence of such phases as g-Al 2 O 3 and KI-Al 2 O 3 in the Al 2 O 3 -H 2 O system. Detailed analysis of the original publications reveals inconsistencies in calculating the phase boundaries of the g-Al 2 O 3 19 and possible effects of impurities.…”

“…3 However, the works of Torkar and colleagues 19,20,23 surprisingly report the presence of such phases as g-Al 2 O 3 and KI-Al 2 O 3 in the Al 2 O 3 -H 2 O system. Detailed analysis of the original publications reveals inconsistencies in calculating the phase boundaries of the g-Al 2 O 3 19 and possible effects of impurities. 20 To the best knowledge of the author, the phase diagrams proposed by Torkar and colleagues have not been confirmed experimentally by other workers.…”