Slurry Erosion Behaviour of AlSiN Based HVOF Coatings: Effect of Impact Angle

Abstract

In this work AlSiN coating were deposited on AA 6082 in three different ratios of aluminium and silicon (%wt) by HVOF process and investigated the effect of different impingement angles under slurry erosion conditions as compared to uncoated AA6082. Jet-type slurry erosion test rig was used and effect of three parameters namely impact velocity, impact angle and slurry concentration on slurry erosion of uncoated AA6082 and AlSiN coated AA6082 was investigated. Microhardness was varied from (1875HV to 1471HV) by varying Al content from (90% to 60%). Dominant erosion mechanism found to be formation of crater and abrasion groves, ploughing in the removal of coating for all combination of AlSiN. Wear rate was found to be high at 300 (ductile mode (Si: 10%)), as the volume of Sicontent was increased to 40%, the mode of erosion mechanism was changed to mixed mode (ductile and brittle) at 600. Slurry rate was linearly varying with respect to impact velocity and slurry concentration.