Wear and corrosion behavior of laser clad Cr₃Si reinforced intermetallic composite coatings

Wear and corrosion are two of the three most frequently encountered failure modes for mechanical components working under aggressive conditions. Extending the service life of mechanical components by surface engineering methods is of critical importance from both the technological and economical point of view. In this paper, novel rapidly solidified wear and corrosion resistant Cr₃Si reinforced intermetallic composite coatings were fabricated on a substrate of austenitic stainless steel 1Cr18Ni9Ti by laser cladding using Cr-Si-Ni elemental powder blends. Microstructure, hardness, room-temperature dry sliding wear and electrochemical corrosion behavior of the laser clad composite coatings were investigated as a function of the Cr₃Si volume fraction. Results show that the laser clad composite coatings have a rapidly solidified microstructure consisting of Cr₃Si primary dendrites and interdendritic matrix of Cr-Ni-Si ternary silicide. Volume fraction of the primary Cr₃Si dendrites was shown to have a remarkable influence on hardness, wear and corrosion resistance of the laser clad composite coatings. The higher the volume fraction of Cr₃Si, the higher the hardness and the wear and corrosion resistance of the laser clad composite coatings.