Thermal and Wear Behavior of Glass Fiber-Filled Functionally Graded Material-Based Polyamide 66 Spur Gears Manufactured by a Novel Technique

This research work presents a modified mathematical method to estimate the specific wear rate of spur gears for specified service conditions by calculating the coordinates of the point on the involute of gear tooth profile. This work stands apart in a way that an entirely novel manufacturing process developed in-house is used to fabricate functionally graded materials (FGMs) based thermoplastic gears, which have never been explored before, and the specific wear rate of manufactured gears is estimated using the proposed method. FGM and homogeneous gears are manufactured by means of an especially designed mold and a punch. Polyamide 66 (PA66) filled with 15 wt. % and 30 wt. % glass fibers is used to fabricate FGM and homogeneous gears. Neat PA66 gear is also fabricated for comparative study. Gradation in FGM gears is verified by scanning electron microscope (SEM) analysis and hardness measurements. Thermal and wear tests of the gears are conducted over a range of rotational speed (500–1700 rpm) and torque (0.8–3.2 N·m). Thermal and wear behavior of developed gears is successfully analyzed using Taguchi methodology and analysis of variance (ANOVA). The service life of FGM gears is found to be superior as compared to unfilled and homogeneous gear. FGM gear filled with 30 wt. % glass fiber exhibited minimum gear tooth surface temperature and specific wear rate among all the fabricated gears.