The reciprocating wear behaviour of TiC–304L stainless steel composites prepared by melt infiltration

Abstract

TiC-based ceramic–metal composites, or cermets, are widely used in applications requiring wear and corrosion resistance. In the present work, a family of novel TiC–stainless steel (grade 304L) cermets has been developed using vacuum melt infiltration (1500°C/1h), with steel binder contents varied from 5 to 30vol%. Microstructural analysis showed a homogenous distribution of TiC within the steel binder, with mean TiC grain sizes of ∼6μm. Increasing the steel content resulted in an increase in the indentation fracture resistance and a decrease in the hardness. The reciprocating wear resistance of the cermets was assessed using a ball-on-flat geometry, using a WC–Co sphere dry sliding on the polished cermet surface. It was shown that there is an increase in the specific wear rate with both increasing load and binder content. Similarly, a higher coefficient of friction was observed with higher steel binder contents. The morphology of the worn surface was investigated using scanning electron microscopy, and associated energy dispersive X-ray spectroscopy, to more fully understand the operative wear mechanisms. Evidence of a transition from two- to three-body abrasive wear was observed, together with the formation of a tribolayer, indicating that adhesive wear was also occurring.