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Direct Tape Casting of Nanosized Al 2 O 3 Slurries Derived from Autogenous Nanomilling
Author(s) -
Vozdecky Pavel,
Roosen Andreas,
Knieke Catharina,
Peukert Wolfgang
Publication year - 2010
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2009.03597.x
Subject(s) - materials science , slurry , tape casting , ceramic , sintering , microstructure , grinding , micrometer , nanoparticle , composite material , surface roughness , casting , particle size , viscosity , surface finish , suspension (topology) , metallurgy , chemical engineering , nanotechnology , physics , mathematics , engineering , homotopy , pure mathematics , optics
Nanoparticles offer many advantages in the manufacture of ceramic products concerning processing and final properties, but are still difficult to process, and not all ceramic powder compositions can be obtained commercially like, e.g., α‐alumina. In this paper, the production of α‐alumina nanosized particles with a median size <60 nm by a wet grinding process in a highly concentrated suspension of up to 49 wt% solid content starting from a commercial microsized powder is presented. Furthermore, the subsequent direct processing of these suspensions to ceramic green tapes via tape casting is performed. The effect of nanosized α‐Al 2 O 3 powders on the viscosity of slurries, the casting process, binder burnout, and sintering behavior is characterized. Flat and crack‐free sintered substrates with a density >95%TD, a submicrometer microstructure, and a translucent appearance could be obtained. A decrease of the sintering temperature, an improvement of the mechanical strength, and a lower surface roughness were achieved through the use of nanoparticles compared with particles in the micrometer size range.