Production of an erosion resistant coating of a nickel-chromium-iron-boron-silicon alloy on a metal component, notably for the leading edges of high speed aircraft and helicopters

摘要

#CMT# #/CMT# Production of an erosion resistant coating on a metal component comprises: (a) the coating is applied by thermal spraying; (b) the coated component is raised, under vacuum, to 250 to 400[deg]C and held at temperature for 5 to 30 minutes; (c) the temperature is raised to 800 to 950[deg]C and held at temperature for 5 to 30 minutes; (d) the temperature is then raised to 900 to 1100[deg]C in a protective gas and under a pressure of 200 to 600 mm/Hg to provoke the liquid phase sintering of the coating above the melting temperature of the coating alloy; (e) the component is cooled to ambient temperature. #CMT#USE : #/CMT# The invention is used for the provision of an erosion resistant coating on a metal component, notably for such applications as the leading edges of aircraft and helicopters flying at high speeds. #CMT#ADVANTAGE : #/CMT# Allows the provision of a coating with extremely little porosity and, by consequence, resistant to erosion whilst having an elevated resistance to vibrations and a satisfactory elasticity for the coating. #CMT#METALLURGY : #/CMT# The coating applied by thermal spraying has a thickness of between 20 and 360 mu m (claimed). Advantageously the coating is of a nickel-chromium-iron- boron-silicon (Ni-Cr-Fe-B-Si) alloy with the following composition (by wt.%) : (a) 0.5 to 1.5 carbon; (b) 10.0 to 26.0 Cr; (c) 1.5 to 10.0 Fe; (d) 1.5 to 4.5 B; (e) 2.5 to 5.0 Si; (f) remainder Ni (claimed). Advantageously the coating contains 10 to 70, by preference 15 to 60 wt.% of hard material, notably carbides or borides of the elements chromium, titanium, tungsten, tantalum, molybdenum and/or niobium, and most notably tungsten carbide with 4 to 20 wt.% of cobalt (claimed).