E. Irissou, Industrial Materials Institute / -National Research Council Canada, Boucherville, QC, Canada; J. G. Legoux, B. Arsenault, C. Moreau, National Research Council Canada (CNRC-NRC), Boucherville,, QC, Canada
Coating build-up mechanisms and properties of cold sprayed aluminum-alumina cermets were investigated. Three spherical aluminum powders having average diameter of 35, 70 and 105 microns were compared. Those powders were blended with alumina at several different concentrations. Coatings were produced using a commercial low pressure cold spray system. Pure aluminum and cermets coatings were characterized using electronic microscopy, x-ray microanalysis, x-ray diffraction. Bond strength, abrasion and salt spray corrosion tests were also performed to evaluate coating performances. In-flight particle velocity and deposition efficiency were monitored for all experimental conditions. It is shown that the critical velocity is function of both, the particle average size and size distribution and the alumina concentration in the blended powder. Correlations between spray conditions such as particle velocity and size, deposition efficiency and alumina concentration are established with coating properties. For cold spraying of a combination of ductile and brittle powders, coating formation mechanisms are explained with regards to phenomenological model.
Summary: Coating build-up mechanisms and properties of cold sprayed aluminum-alumina cermets were investigated. Three spherical aluminum powders having average diameter of 35, 70 and 105 microns were compared. Those powders were blended with alumina at several different concentrations. Coatings were produced using a commercial low pressure cold spray system. Pure aluminum and cermets coatings were characterized using electronic microscopy, x-ray microanalysis, x-ray diffraction. Bond strength, abrasion and salt spray corrosion tests were also performed to evaluate coating performances. In-flight particle velocity and deposition efficiency were monitored for all experimental conditions. It is shown that the critical velocity is function of both, the particle average size and size distribution and the alumina concentration in the blended powder. Correlations between spray conditions such as particle velocity and size, deposition efficiency and alumina concentration are established with coating properties. For cold spraying of a combination of ductile and brittle powders, coating formation mechanisms are explained with regards to phenomenological model.
