Open AccessCermet composite thermal spray coatings for erosion and corrosion protection in combustion environment. Semi-annual report, August 14, 1996--January 14, 1997
Author(s) -
B.F. Levin,
J. N. DuPont,
A. R. Marder
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/492379
Subject(s) - cermet , materials science , thermal spraying , corrosion , metallurgy , composite number , powder metallurgy , ceramic , volume fraction , erosion , metal , combustion , composite material , microstructure , coating , paleontology , biology , chemistry , organic chemistry
Research is being conducted to determine the optimum ceramic/metal combination in thermally sprayed metal matrix composite coatings for erosion and corrosion resistance in new coal-fired boilers. The cermet composites will be produced using powder metallurgy and electrodeposition. Model Ni-Al{sub 2}O{sub 3} cermet coatings with varying alumina fractions were produced. During this period, powder processed and electrodeposited composites were tested in the erosion simulator (Al{sub 2}O{sub 3} erodent, 40 m/s velocity, 90{degree} impact angle) and their relative erosion resistances were determined. It was found that electrodeposited Ni-Al{sub 2}O{sub 3} composites containing small Al{sub 2}O{sub 3} particles (1{mu}m)s showed better erosion resistance than powder processed composites with large Al{sub 2}O{sub 3} particles (12{mu}m). Also, an increase in volume fraction of Al{sub 2}O{sub 3} particles in powder processed alloys led to decreased erosion resistance. For both powder processed and electrodeposited Ni-Al{sub 2}O{sub 3} composites, addition of hard Al{sub 2}O{sub 3} particles did not improve erosion resistance compared with pure Ni