Fabrication of TiC/Fe–Ni cermet coatings by reactive thermal spraying of Fe–Ti–Ni–C composite powder

Abstract

A mixture of ferrotitanium, nickel powders and sucrose was heated with an intention of carbonising the sucrose. The tiny ferrotitanium, nickel particles are bound by the carbon obtained from pyrolysis of the sucrose to form a unique structure of Fe–Ti–Ni–C composite powder for reactive thermal spraying. The carbon is a reactive constituent as well as the binder in the composite powder. TiC/Fe–Ni cermet coating was prepared by reactive plasma spraying of this powder. A mass of TiC particles were in situ synthesised and uniformly distributed in the Fe–Ni alloy matrix without residuals of raw materials in the coating. The coating is consisted of two different areas: one is the composite area, where lots of spherical fine TiC particles (100–500 nm) are homogeneously distributed within the Fe–Ni alloy matrix; the other is a small fraction of TiC accumulation. The volume fraction of composite area is >87%.

Keywords:

• Fe–Ti–Ni–C powder
• Sucrose
• Cermet coatings
• Reactive thermal spraying