Effect of Friction-stir Processing on the Wear Rate of WC-based MMC Coatings Deposited by Low Pressure Cold Gas Dynamic Spraying

Tuesday, May 12, 2015: 11:10 AM
Room 102A (Long Beach Convention and Entertainment Center)
Mr. Sayed Hossein Ashrafizadeh , University of Alberta, Edmonton, AB, Canada
Mr. Adrián Lopera-Valle , University of Alberta, Edmonton, AB, Canada
Dr. Adrian Gerlich , University of Waterloo, Waterloo, ON, Canada
Dr. André McDonald , University of Alberta, Edmonton, AB, Canada
A low-cost, low-pressure (less than 1MPa) cold spray unit was used to deposit tungsten carbide (WC)-based metal matrix composite (MMC) coatings on low carbon steel substrates. The coatings were then friction-stir processed (FSP) by using a flat cylindrical tool. Scanning electron microscopy (SEM), image analysis, micro-hardness testing, and ASTM Standard G65 dry abrasion wear testing were conducted to study the influence of FSP on the coating properties and its wear rate. It was found that FSP increased the hardness of the WC-based MMC coatings. Image analysis indicated that this increase in hardness was attributed to more uniform distribution of WC particles within the matrix and shorter mean free path after FSP. As a result of that, the abrasion wear rate of the coatings after FSP decreased compared to that of as-sprayed coatings. This suggested that FSP can be considered as a method to improve the wear properties of MMC coatings.