High Temperature wear of thermal sprayed NiCr-Cr3C2 Coatings

NeCr-Cr3 C2 coating having three different volume fraction of Cr3 C2 particles in the matrix will be deposited on stainless steel and Ni-base superalloy. Each type of coating with nano-structure and conventional grain size will be studied. These coatings will be deposited by HVOF techniques. The microstructural features and mechanical properties of each type of coatings will be evaluated. The sliding wear behaviour of these coatings at elevated temperature upto 800C will be studied for a range of sliding velocity and applied load. The worn surface and the surface beneath the worn surfaces will be examined in SEM to understand the mechanism of material removal. Depending on the mechanism of material removal, wear mechanism map showing the prevalance of various material removal mechanism as functions of wearing conditions will be constructed and most economical operating condition will be identified. Further study with EPMA or TEM may be carried out to understand the method to reduce the wear rate in minimum wear rate regime. Thus the work will directly bring out the influence of carbide volume fraction, structure and properties of the coatings on its wear behaviour. This study will be extrapolated to nano-tribology of bio materials and electronic materials.