Failure and wear analysis of poly(butylene terephthalate) nanocomposite spur gears

This paper investigates the wear and failure mechanisms in poly(butylene terephthalate) (PBT) nanocomposite gear pairs. An image-based technique was employed to measure the gear tooth wear. Image acquisition process was further used to identify tooth wear patterns and explore gear failure mechanisms. Gear test results revealed that the inclusion of nanofillers increased the load-bearing capacity and wear resistance. Gear failure mode was altered from thermal tooth deflection for PBT to dominant crack-induced tooth fracture for the nanocomposites. Morphology analysis of the worn teeth indicated the transition of wear mechanism from adhesive for pure PBT to abrasive type with the inclusion of nanofillers. Furthermore, the strain field on the gear teeth was analyzed by applying digital image correlation (DIC) technique.