The Government of the United States of America, as represented by the Secretary of the Navy
发明人:
Wollmershauser James A.,Drazin John,Kazerooni Dana A.,Feigelson Boris N.,Gorzkowski, III Edward P.
申请号：
US201715730817
公开号：
US2018111841(A1)
申请日:
2017.10.12
申请国别(地区):
美国
年份:
2018
代理人:
摘要：
A process for producing metastable nanocrystalline alpha-alumina (α-Al2O3) having particle sizes smaller than 12 nm. Starting crystallites of α-Al2O3 having a particle size larger than 12 nm, typically on the order of about 50 nm, are ball-milled at low temperatures to produce a nanocrystalline α-Al2O3 powder having a particle size of less than 12 nm, i.e., below the theoretical room temperature thermodynamic size limit at which α-Al2O3 changes phase to γ-Al2O3, wherein the powder remains in the α-Al2O3 phase at all times.
