The tribogram: An AFM-based nanoscale tribocorrosion analysis method incorporating tip convolution effects

Abstract

Fretting corrosion, or mechanically assisted crevice corrosion (MACC), at a modular taper junctions of hip implants remains a significant clinical concern. This study introduced a novel atomic force microscopy (AFM)-based method to monitor real-time nanoscale wear and tribocorrosion progression on low carbon cobalt-chromium-molybdenum (CoCrMo) alloy by inducing repetitive nanowear at a fixed location under air (wear only) and phosphate-buffered saline (PBS, wear and corrosion). We visualized and quantified wear evolution in situ using a “tribogram” (height vs. sliding distance vs. wear cycles) while addressing tip convolution effects on large discrepancies in mass balance analysis between bearing-based and calculated true volumes. The tribogram revealed reduced wear in PBS compared to air, possibly due to repassivating oxide effects (topographical rises in tribogram).