Method for superfine nanocrystallization of laser cladding coating on surface of titanium alloy in ice environment

• Main Authors: LIU KEGAO, LIU PENG, HUO YUSHUANG, LI JIANING, SHI LEI, YUAN XINGDONG, LUO HUI, ZHANG YUANBIN
• Format: Patent
• Language: English
• Published: 29.04.2015
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The invention discloses a method for superfine nanocrystallization of a laser cladding coating on the surface of a titanium alloy in an ice environment. The method comprises the following steps: uniformly mixing Stellite4 and mixed powder of B4C and Zn at a certain ratio and blending with a sodium silicate solution into paste, wherein the size of Stellite4 is 1-370 mu m, and the sizes of B4C and Zn are 4-400 mu m; uniformly coating the surface of the titanium alloy with the pasty mixed powder, wherein the thickness of the coating is 0.2-2 mm; drying the coating naturally; placing a prepared sample in a plastic container with water is above over the sample, and then placing the container in a freezing chamber so that the solution is completely solidified; and cladding the surface of the sample with a laser beam, and meanwhile protecting the surface of the sample with argon. Technological parameters are as follows: laser power 450-3500W, scanning speed 1-18mm/s and protection air pressure 0.1-1.2 MPa. Through the method, a superfine nano coating remarkably improved in hardness and surface appearance quality can be obtained on the surface of the titanium alloy.