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Boron Nitride Coatings on Oxide Substrates: Role of Surface Modifications
Author(s) -
Borek Theodore T.,
Qiu Xiaomei,
Rayfuse Leann M.,
Datye Abhaya K.,
Paine Robert T.,
Allard Lawrence F.
Publication year - 1991
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.1151-2916.1991.tb06804.x
Subject(s) - materials science , oxide , coating , chemical engineering , boron nitride , surface modification , boron oxide , yield (engineering) , monolayer , nitride , boron , layer (electronics) , composite material , nanotechnology , chemistry , metallurgy , organic chemistry , engineering
Physical mixtures of a BN polymeric precursor with oxides such as MgO, Al 2 O 3 , and TiO 2 have been found to yield crystalline, tightly adherent coatings of hexagonal BN on the oxide surface, after appropriate heat treatments. In every instance, the BN (0001) basal planes are parallel to the oxide surface. Generally, the coating conforms very well to the contours of the oxide surface. However, an exception was the silica surface where no coatings were observed. It appears that the surface silanols condense to form siloxanes at high temperatures, yielding a surface that is unreactive and unable to bind to the BN. Modification of the silica surface by incorporation of a monolayer of titania dramatically alters the ability of the silica to stabilize BN coatings. It was found that stable BN coatings could be obtained when the silica surfaces were thus modified.