Microstructure and properties of laser remelt YPSZ coatings

CO₂ laser system was used to remelt YPSZ (yttria partially stabilized zirconia, 8% Y₂O₃ -ZrO₂) coatings.The microstructure, phases and microhardness of the coatings were studied. Results show that after rapid melting and solidification by laser beam, the porosity and the crack in the YPSZ coatings are decreased, meanwhile the strength and toughness of YPSZ coatings are increased.This change is due to the variation of phases. The YPSZ coatings treated by laser remelting is composed of lots tetragonal and few cubic phases.Tetragonal phase is the main reason to improve the mechanical properties of coating surface.