Tribological properties of laser surface texturing and molybdenizing duplex-treated Ni-base alloy

Abstract

Laser surface texturing (LST) and surface molybdenizing duplex-treatment was performed on Ni-base alloy in order to improve its wear resistance at high temperature. Surface molyb-denizing was performed on the laser surface textured Ni-base alloy by a double glow plasma surface alloying technology. The friction and wear properties of the duplex-treated, the single-treated, and the untreated alloys were tested on a ball-on-disk tribometer by rubbing against an alumina ceramic ball from room temperature to 600°C. The topography of the laser surface textured dimples was measured by a white light interfer-ometer and optical microscope. The dimples are 150-200 μm in diameter and 45-50 μm in depth. The distance between the dimples is 500 μm. The molybdenized layer is approximately 20 μm in thickness. The elastic modulus of Ni-base alloy is improved by molybdenizing. After texturing and the molybdenizing duplex treatment, the friction coefficient of the Ni-base alloy decreases from 0.38 to 0.26 at room temperature and from 0.42 to 0.34 at 600°C. The wear rate of the duplex-treated alloy is much lower than that of the pristine alloy at 600°C due to the textured dimples storing lubricious oxides. © Society of Tribologists and Lubrication Engineers.