2026 Ingber Abrasive Wear Near Surface Microstructure

The microstructure and properties in the near-surface region of two high-carbon metastable austenitic steels after two-body abrasive wear were studied. The samples were subjected to wear loads in a range of 8–32 N (corresponding to approximately 0.1–0.4 MPa). Vickers hardness measurements on the worn surface as well as nanoindentation measurements on the cross section present a significant hardness increase from the bulk toward the surface of up to 400%. Electron channeling contrast imaging was utilized to assign the indents from the nanoindentation measurements to the martensitic or austenitic phase. Within a subsurface layer with a thickness of a few microns, it was impossible to distinguish a phase via these images. Magnetic force microscopy revealed a few microns thick martensitic layer, which is the main cause of the significant hardness increase in the near-surface region. No considerable influence of the wear load (within the tested load range) on the resulting microstructure and mechanical properties was found. Transmission electron microscopy images reveal a grain size of several nanometers within the martensitic subsurface layer, which accounts for the observed ductility on the worn surfaces, despite the inherent brittleness typically associated with high-carbon martensite.