A METHOD OF DEPOSITING AN EROSION, CORROSION AND CAVITATION RESISTANT DUPLEX COATING FOR DEPOSITING ON HYDRO TURBINE COMPONENTS

摘要

The invention relates to a method of deposition of thin films of ternary metal nitrides by Pulsed Direct Current (DC) reactive magnetron sputtering on plasma nitrided surface to achieve duplex coating on martensitic 13Cr-4Ni and AISI 410, 16Cr-5Ni, austenitic 18Cr- 8Ni and manganese steel substrate used in forming hydro turbine components, wherein the ternary metal nitride such as Ti-Si-N and Zr-W-N thin film is deposited upto 15 microns on white layer free nitrided substrate and wherein the sputtering is carried out using nitrogen and argon gases in a vacuum chamber at a temperature upto 300oC with a target power in the range of 300- 600 W and process pressure in the range of 1.0-2.0 mbar with the deposition time of 4-5 hrs to achieve film thickness of 10-15 microns.