Hertzian indentation response of TiC-316L stainless steel cermets

Titanium carbide (TiC) based cermets are commonly used in a variety industries because of their high hardness, strength and wear resistance. In many applications, such as bearings, cermets are exposed to 'Hertzian-type' loading scenarios. The present work is focused on the Hertzian indentation contact damage of a new family of TiC-316L stainless steel cermets. Samples were fabricated using a vacuum melt-infiltration procedure, at 1550 degrees C for between 60 and 240 min, with the steel binder contents ranging from 10 to 30 vol%. Various diameter WC-6Co spheres (nominally 10 vol% Co), from 1.19 mm to 3.97 mm, were used for indentation. The applied indentation loads were varied from 250 N to 2000 N. Indentation stress-strain curves were plotted to study the effects of differences in the cermet microstructure and the loading condition. 'Ideal' Hertzian elastic responses were also calculated, to demonstrate the deviation of the curves. It is shown that the materials deform in a 'quasi plastic' manner, with evidence of 'strain-hardening' phenomena.