Experimental studies on the durability of PA6-PP-CaCO3 nanocomposite gears

Nanocomposite gears based on Polyamide 6/Polypropylene (PA6/PP 67/33) blend containing 2.5 to 10 phr of nano-CaCO3 and 5 phr of maleated polypropylene (PP-g-MAH) as compatibilizer were produced by injection molding. The morphology was studied using scanning electron microscopy. The wear and temperature of gears teeth as well as gears working lives were characterized by employing a gear test rig under two different output torques including 8.9 and 14.8 Nm. In all experiments, the teeth’s temperature and wear values for driver gear were higher as compared to those of driven gear. The incorporation of 2.5 and 5 phr nano-CaCO3, led to the reduction of temperature and wear rate of gears. The wear rates of gears containing 2.5 phr of nano-CaCO3, under the torque of 8.9 and 14.8 Nm, were 60 and 83% lower than those of neat PA6 gears respectively. The maximum gear life under the torque of 14.8 Nm (63000 revolutions) was observed in nanocomposite gears containing 2.5 phr of nano-CaCO3 which was nearly 200% higher than that of neat PA6 gears (21000 revolutions). The raise of Polymer based gears performances as a result of CaCO3 nanoparticles inclusion may be attributed to the improvements of gear teeth flexural, wear and heat resistance