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In ‐ situ densification of combustion synthesized coatings
Author(s) -
Puszynski Jan A.,
Miao Shuxia,
Stefansson Bjarni,
Jagarlamudi Sunil
Publication year - 1997
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690431321
Subject(s) - nial , materials science , combustion , intermetallic , microstructure , ceramic , in situ , carbon fibers , metallurgy , particle (ecology) , phase (matter) , chemical engineering , composite material , chemistry , composite number , organic chemistry , alloy , engineering , oceanography , geology
Dense intermetallic and ceramic (alumina based) coatings can be formed in situ during simultaneous combustion synthesis and densification in the field of centrifugal forces. Both microstructure and composition of alumina‐based coatings formed during alumino‐thermal reduction of oxides can be altered by an introduction of additives such as ZrSiO 4 , SiO 2 , Na 2 CrO 4 , and carbon. The activation energy and frequency factor for the Ni‐Al reacting system consisting of equal atomic amounts of Ni and Al powders with an average particle size of 5 μm were measured using a nonisothermal technique, which were equal to 1.05 × 10 5 J/mol and 1.017 × 10 8 s −1 , respectively. A mathematical model of in‐situ densification of a single‐phase combustion product (NiAl) in the field of centrifugal forces was developed and explored.