Effect Of Particle Morphology On The Tribological Behavior Of Cold Sprayed Al MMC Coatings

Thursday, May 14, 2015: 9:20 AM
Room 102A (Long Beach Convention and Entertainment Center)
Mr. J. Michael Shockley , McGill University, Montreal, QC, Canada
Prof. Richard R. Chromik , McGill University, Montreal, QC, Canada
Dr. Sylvie V. Descartes , INSA de Lyon, Lyon, France
Dr. Phuong Vo , National Research Council Canada, Boucherville, Montreal, QC, Canada
Cold sprayed pure aluminum or Al-Al2O3 coatings are used for repair and corrosion protection for magnesium aerospace gearbox components. Al-Al2O3 coatings are sprayed from an admixed feedstock of Al and Al2O3 powders, and during deposition some Al2O3 particles are recovered into the final coating. In this study, the effect of Al2O3 particle morphology on the tribological performance was examined, where the more common angular particle morphology was compared to spherical particles. Cold sprayed Al-Al2O3 coatings were deposited using angular and spherical Al2O3 powders and subjected to both dry sliding wear tests and high pressure torsion. The effect of Al2O3 morphology was explored in terms of Al2O3 recovery in the coating, microstructure, and the subsequent tribological behavior in dry sliding. Microstructures from high pressure torsion experiments revealed different deformation mechanisms near Al2O3 particles of different morphology. Comparisons to near surface microstructures from dry sliding wear led to correlations between the two testing methods that helps to explain the differences in wear performance due to particle morphology.