Preparation of Ti_2AlC MAX Phase Coating by DC Magnetron Sputtering Deposition and Vacuum Heat Treatment

摘要

Due to the excellent corrosion resistance and high irradiation damage resistance,Ti_2AlC MAX phase is considered as a candidate for applications as corrosion resistant and irradiation resistant protective coating.MAX phase coatings can be fabricated through firstly depositing a coating containing the three elements M,A,and X close to stoichiometry of the MAX phases using physical vapor deposition,followed by heat treatment in vacuum.In this work,Ti-Al-C coating was prepared on austenitic stainless steels by reactive DC magnetron sputtering with a compound Ti_(50)Al_(50) target,and CH4 used as the reactive gas.It was found that the as-deposited coating is mainly composed of Ti_3AlC antiperovskite phase with supersaturated solid solution of Al.Additionally,the ratio of Ti/Al remained the same as that of the target composition.Nevertheless,a thicker thermally grown Ti_2AlC MAX phase coating was obtained after being annealed at 800℃ in vacuum for 1 h.Meanwhile,the ratio of Ti/Al became close to stoichiometry of Ti_2AlC MAX phases.It can be understood that owing to the higher activity of Al,it diffused quickly into the substrate during annealing,and then more stable Ti_2AlC MAX phases transformed from the Ti_3AlC antiperovskite phase.