Failure analysis of POM ternary nanocomposites for gear applications: Experimental and finite element study

Abstract

The main purpose of the present study is to assess the failure behavior of polyoxymethylene/carbon black/CaCO3 ternary nanocomposite gears by employing an experimental gear test setup and a gear renewal technique. The failure-related factors including surface temperature, tooth wear, and failure analysis at macro- and micro-scales were studied. The tooth surface temperature was measured continuously based on an online-measuring approach. The tooth wear was calculated using microscopic images and software analysis. The maximum contact stress on meshing teeth surfaces was specified by finite element analysis. According to SEM micrographs, the application of both nanostructures contributed to a more uniform distribution of each nanophase within the POM matrix. The gear test results indicated an enhanced tooth resistance and service life of up to 58% and 125%, respectively, for ternary nanocomposites relative to neat POM gears. The tooth surface temperature was reduced for nanocomposite gears due to the promoted heat transfer and thermal stability. The tooth deformation and cracking were highly suppressed for ternary nanocomposite gears at failure. The evaluation of teeth surface damages at micro-scale revealed the suppression of plastic flow and material adhesion for ternary nanocomposites.