Preparation, microstructure and tribological properties of Ni3Al intermetallic compound coating by laser cladding

Single Ni3Al intermetallic compound phase coating was successfully in-situ synthesized by laser cladding with preplaced Ni and Al mixed powders. The phase composition and microstructure of the Ni3Al coating were studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The effects of laser cladding parameters on the microstructure and tribological properties of the Ni3Al coating were investigated. It was found that the laser power density and energy density had a crucial influence on the microstructure and tribological properties of the Ni3Al coatings. The Ni3Al coating synthesized under the lower power density and energy density had a dense and fine microstructure as well as some excellent properties such as higher and homogeneous distribution microhardness, lower friction coefficient and wear rate. (C) 2009 Elsevier Ltd. All rights reserved.