Dilution characteristics of ultrasonic assisted laser clad yttria-stabilized zirconia coating

Yttria-stabilized zirconia (YSZ) coatings with improved microstructures and properties were deposited using the novel ultrasonic assisted laser cladding technique. The effect of ultrasonic vibration on the evolution of microstructures and the element distribution characteristics was investigated. It was found that application of ultrasonic vibration in the laser cladding process changed the cross-sectional morphology of coatings, and the microstructures were refined. With the ultrasonic vibration, the stepped element transition within the coating deposited without ultrasonic vibration changed to a approximately linear transition. Additionally, the dilution rate between the coating and substrate increased due to the complete mixing of the molten substrate with the molten filler powders caused by the ultrasonic nonlinear effects. These findings indicate that the ultrasonic vibration could simultaneously control the microstructures and dilution characteristics of coatings to improve the coating bonding strength with the substrate. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.