Laser cladding of cobalt alloy with ceramic nanopowder on steel

Abstract

There is a need in different industry sectors (automotive, aeronautics, and tooling industries) to improve the performance of material surface under wear and corrosion environments, which cannot be fulfilled by conventional surface modifications and coatings.The aim of this work is to produce cobalt alloy nanocomposites coatings on steel by laser cladding. They are obtained by laser melting blown powder on the steel surface. The powder precursor is obtained by mechanical milling of cobalt alloy micropowder with yttria or titanium carbide nanopowder. A comparison between conventional stellite laser cladded and stellite with nanoparticles laser cladded coatings, regarding their microstructure and mechanical properties (hardness, wear resistance), is established. The yttria particles are segregated into the intergranular space, while the titanium carbide particles are dispersed in both the dendrites and interdendrite space. The effect is the growing of finer and equiaxial dendrites when using yttria, while the titanium carbide nanoparticles introduce an important reinforcement of the cobalt alloy matrix.There is a need in different industry sectors (automotive, aeronautics, and tooling industries) to improve the performance of material surface under wear and corrosion environments, which cannot be fulfilled by conventional surface modifications and coatings.The aim of this work is to produce cobalt alloy nanocomposites coatings on steel by laser cladding. They are obtained by laser melting blown powder on the steel surface. The powder precursor is obtained by mechanical milling of cobalt alloy micropowder with yttria or titanium carbide nanopowder. A comparison between conventional stellite laser cladded and stellite with nanoparticles laser cladded coatings, regarding their microstructure and mechanical properties (hardness, wear resistance), is established. The yttria particles are segregated into the intergranular space, while the titanium carbide particles are dispersed in both the dendrites and interdendrite space. The effect is the growing of finer and equiaxial dendrites when using yttria, while t...