Influence of the type of interface on the tribological characteristics of ICVI generated SiCf/SiC composites

The SiCf/SiC ceramic matrix composites find applications in structural, wear resistance and high temperature applications as they are quite superior to their monolithic counter parts due to their improved flaw tolerance, large work of fracture and non-catastrophic failure behaviour. In this investigation, three types of SiCf/SiC composites, i.e., SiCf/SiC composite with carbon interface, SiCf/SiC composite with boron nitride interface and SiCf/SiC composite with boron nitride interface subjected to an intermediate heat treatment have been made via isothermal and isobaric chemical vapour infiltration technique using Nicalon ceramic grade SiC fibres. The density achieved in all the three types of composites is around 2.6–2.7 g/cc. The sliding wear/friction and solid particle erosion experiments were carried out on these composites using a pin-on-disc set up and jet erosion test rig respectively. The composites with carbon interface show higher hardness, lower sliding wear and erosion losses compared to the composite with boron nitride interface with and without intermediate heat treatment. To substantiate the slide wear and erosion data, scanning electron microscopic features have been examined.

► SiC/SiC composites with carbon interface show better wear and erosion resistance in addition to good mechanical properties.
► The intermediate heat treatment given to the SiC/SiC composites with boron nitride interface improves the tensile properties, fracture toughness etc. but wear resistance and erosion point of view it degrades.
► SiC/SiC composites with boron nitride interface improves show poor wear and erosion resistance.