Hydropower generation from the himalayan rivers in india and similar other regions of the world, face challenge in the form of silt-laden water which can erode the turbine blades and from cavitation damages. the hydraulic machinery industry is interested in the continuing search for economical materials and suitable coatings with high resistance to cavitation and silt erosion damage. the aim of the present study is to develop a polyurethane coating reinforced with b4c and sic nano particles with different weight percentages on 16cr-5ni martensitic stainless steel and to understand the silt erosion and cavitation erosion performance of these coatings. the synergic effect of sand erosion and cavitation is more pronounced than their individual effects and it is complex phenomenon, consisting of several simultaneous and interacting processes. to study most complex synergic effect of sand erosion and cavitation we developed first state of art facility in iits and in the world, which gives a great thrust for research work.