Optimization of laser texture geometry and resulting functionality of nickel aluminium bronze for landing gear applications

Abstract

Nickel-aluminium bronze (NAB) is adopted in certain crucial applications such as nut threads of actuator screw assembly in nose landing gear, which forms the critical weakest link for landing gear operation. Surface engineering of such critical aircraft parts made of softer materials is required to improve their safety design life. This paper reports optimization of nanosecond laser parameters for enhancing the quality characteristics of surface textures formed on NAB. These characteristics include micro-texture depth, aspect ratio, average surface roughness, maximum height of the profile and kurtosis. Texture diameter and width was computed using an optical microscope. Dimples and grooves with minimum damage were obtained at higher laser power (18 W), moderate scanning speed (500 mm/s) and moderate frequency (50 kHz). The quality ellipse was obtained at moderate power of 14 W, higher scanning speed of 800 mm/s and moderate frequency of 50 kHz. However, the quality of textures deteriorated at moderate laser power (14 W), lowest scanning speed (100 mm/s) and moderate frequency (50 kHz).