Mechanical Behavior and Sliding Wear Studies on Iron Aluminide Coatings Reinforced with Titanium Carbide

Mahdi Amiriyan,Sylvio Savoie,Houshang Alamdari,Carl Blais,Robert Schulz,Mario Gariépy

doi:10.3390/met7050177

Abstract

Wear-resistant iron aluminide-based composites were coated on steel substrates with the High-Velocity Oxy-Fuel (HVOF) technique using ball milled Fe3Al and TiC powders as feedstock. The phase composition, microstructure, microhardness, elastic modulus and dry sliding wear performance of unreinforced Fe3Al and Fe3Al–TiC composite coatings (reinforced with 30 and 50 vol. % TiC particles) were evaluated in order to reveal the relationship between the mechanical and tribological behaviors. Compared to the unreinforced coatings, the composite coating with 30 vol. % TiC particles exhibited much greater hardness and higher elastic modulus. The increase of the elastic modulus of the composite coatings did not result in deterioration of sliding wear behavior. The addition of 50 vol. % TiC resulted in a further increase in hardness, however, both composite coatings showed the same elastic modulus. The fractured cross sectional surface of the unreinforced coating showed a weakly bonded microstructure promoting delamination in wear tests, whereas the composite fractured surface showed strong mechanical bonding between the matrix and carbide particles, leading to better cohesion. The Fe3Al–TiC coatings showed almost three orders of magnitude higher wear resistance under the dry sliding wear test compared to the unreinforced coatings.

Highlights

Since the introduction of the Fe–Al intermetallics as corrosion, oxidation and sulfidation resistant candidates for many applications, FeAl and Fe3 Al intermetallics have become a subject of great interest [1,2]
Despite having competitive properties over many intermetallics and metals, iron aluminides suffer from limited ductility at room temperature and poor wear resistance [4]
Studies have shown that coating could be a suitable approach to overcome this drawback, taking advantage of the substrate formability and the properties of iron aluminide on the surface

Summary

Introduction

Since the introduction of the Fe–Al intermetallics as corrosion, oxidation and sulfidation resistant candidates for many applications, FeAl and Fe3 Al intermetallics have become a subject of great interest [1,2]. Fe3 Al has been suggested to be a promising binder phase for ceramic particles, such as hard carbides, for achieving higher wear resistance and better oxidation resistance [3]. Despite having competitive properties over many intermetallics and metals, iron aluminides suffer from limited ductility at room temperature (less than 5%) and poor wear resistance [4]. The mediocre room temperature ductility and poor formability, has limited their utilization as bulk components. Studies have shown that coating could be a suitable approach to overcome this drawback, taking advantage of the substrate formability and the properties of iron aluminide on the surface.

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Conclusion