Obtaining thermal damping metallic porous coating on ceramics by means of supersonic laser spray technique

Abstract

This work presents a novel technique, named supersonic laser spraying, to coat ceramic materials with metals. This technique enables obtaining porous coatings which can act as thermal barriers.In this technique, a laser beam is focused onto the surface of a precursor material in such a way that it is melted in the beam-metal interaction zone. Then, a high-velocity gas jet expels the molten material and propels it to the surface of the substrate, in this case a ceramic substrate. This is an alternative technique to plasma spray.In this work, we present some preliminary results obtained using the supersonic laser spray technique to coat a commercial ceramic plate with an Aluminium alloy using a 3.5 kW CO2 laser and a supersonic jet of Argon.Coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, X-ray diffraction and interferometric profilometry. Preliminary tests on the performance of such coatings as thermal barriers have been also carried out. The results were very promising and showing the great potential of the technique as an alternative to plasma spray.This work presents a novel technique, named supersonic laser spraying, to coat ceramic materials with metals. This technique enables obtaining porous coatings which can act as thermal barriers.In this technique, a laser beam is focused onto the surface of a precursor material in such a way that it is melted in the beam-metal interaction zone. Then, a high-velocity gas jet expels the molten material and propels it to the surface of the substrate, in this case a ceramic substrate. This is an alternative technique to plasma spray.In this work, we present some preliminary results obtained using the supersonic laser spray technique to coat a commercial ceramic plate with an Aluminium alloy using a 3.5 kW CO2 laser and a supersonic jet of Argon.Coatings were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, X-ray diffraction and interferometric profilometry. Preliminary tests on the performance of such coatings as thermal barriers have been also carried out. The results ...