Slurry erosion properties of detonation sprayed and plasma sprayed coatings for materials used in mining environments

Mining industries extensively use pumps for disposing water mixed with slurry. The pump impellers often get eroded while draining the mixture containing solid particles and water. The impeller shafts are commonly made of stainless steels. Though several types of other thermal sprayed coatings are well known, the attention has been focused on plasma and detonation sprayed coatings in the present investigation. An experimental investigation was made involving variations in parameters such as surface velocity, time of erosion and slurry composition using a pot erosion tester. It is observed that mass loss increases with increase in surface velocity and duration of exposure in such conditions. Increase in slurry composition reveals the initial increase in mass loss. However, this trend cannot be overestimated. Surface characterisation studies were made using XRD and SEM. The observations indicate that the SEM morphology for detonation spray coated material reflects better adhesion leading to negligible wear when compared with the plasma sprayed coatings.