Effect of Laser Power on Wear Resistance of Laser Cladding IN738LC Alloy

Abstract

IN738LC alloy is a typical γ’ phase precipitation-strengthened nickel-based superalloy, commonly used in high-temperature components such as gas turbines and aero-engines.In order to further enhance its high-temperature wear resistance, IN738 alloy samples were prepared using laser cladding technology with four different laser powers in a 99.99%pure nitrogen environment, followed by heat treatment at 850 ℃for 24 h.The microstructure and properties were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-temperature friction and wear testing machines and JMatPro software.Results showed that with the increase in laser power, the mean hardness of the samples without heat treatment increased gradually from 40.74 HRC to 41.92 HRC, while the mean hardness of the samples after heat treatment was 43.0 HRC.The average friction coefficients of the samples without heat treatment and after heat treatment at normal temperature were 0.70 and 0.65, respectively.The average friction coefficient at 800 ℃of the samples after heat treatment was 0.35.The wear resistance of the samples first increased and then decreased with the increase in laser power within a certain range of laser power.The wear resistance of the samples prepared at room temperature and at 800 ℃was highest when the laser power was 750 W and 650 W,respectively.The wear resistance of samples prepared under the same laser power at a high temperature of 800 ℃was much better than that at room temperature.

Keywords

• in738lc alloy； laser cladding； laser power； friction and wear