Mechanisms of slurry erosion in coatings of hydro-turbines

Abstract

In power generation sector, efficiency of power plant is an important parameter. In hydrodynamic power plants, the prominent reason for efficiency degradation is slurry erosion (SE), which usually results in the form of damage turbine blades and other components costing to the time and money expenses owing to repair and replacement of parts. Over the passage of years, SE has been noticed as the major fallback of hydro-power industries. The prime operating parameters SE are impact velocity, impact angle, slurry concentration, hardness ratio (hardness of erodent particles to that of target material) as well as size and shape; morphology of slurry particles. Researchers have come up with some solutions to deal with the SE issue such as coatings on turbine blades. Coating are considered as suitable and effective remedies for retention of power plant efficiency. The exhaustive available information about SE phenomenon and associated failure mechanisms of concerned materials, either in coated or uncoated conditions is an indicative of its complex and unpredictable nature. This article is written to discuss the prospects of numerous coatings of hydro-turbine blades, their SE and associated failure mechanisms. Especially where hardness of deposited coating layers plays a prominent role in enhancing the SE resistance.