Investigation and performance analysis of short carbon fiber reinforced polyamide 66 of spur gears

Spur gears are essential components in a mechanical power transmission system used in rotating equipment at varying loads and speeds. In food processing machinery, the PP materials are used but do not provide sufficient material properties. In the present paper, specimens and spur gears are made up of Short Carbon Fiber (SCF) reinforced matrix polyamide66 (PA66) composite materials on an injection molding machine. Carbon steel gears have a low strength-to-weight ratio as compared to polyamide composite gears. These gears produce more noise & vibration due to friction and need proper lubrication and maintenance. Further, inertia in these gears is more, affecting the performance. Tensile and density tests of specimens with a different weight percentage of SCF in PA66 are tested ASTM D 638-14 and ASTM D 792 standards. Tensile test performance on different specimen's results shows that the strength increases up to 40% SCF content then almost remains constant. Further, FEA results show that the total deformation of carbon steel is significantly 97.70% less than PA66 and SCF/PA66 composite spur gears. Under the same torque, the stresses developed in SCF/PA66 composite gear are 11.68% less than in carbon steel gear. Hence composite spur gears have a high potential for good tensile strength and a weight reduction. To be a substitute for carbon steel gear for applications where moderate power and precision motion transmission. It is found that the weight of SCF/PA66 composite spur gears is 5.54 times much less than carbon steel. Finally, these gears are highly recommended for their superior properties and sustainability. The observation of tensile specimen failure with advanced microstructure Field Emission Scanning Electron Microscopy shows that most of the fibers of interfacial bonds pulled out and some agglomerated out of the PA66 instead of breaking. It is observed that due to proper mixing of fibers are evenly distributed in the matrix.