Role of Interfaces on Multi‐length Scale Wear Mechanics of TaC‐based Composites

Abstract

In the current work, contact‐mechanics at different length scale is utilized to correlate damage accumulation in TaC‐based composites. Upon synergistic reinforcement with silicon carbide (SiC) and carbon nanotubes (CNTs), TaC has shown to reduce the wear rate from 10.5 × 10−7 to 4.1 × 10−7 mm3 N−1 m−1 upon fretting (micro‐wear) and from 8.0 to 2.7 mm3 N−1 m−1 upon micro‐scratching (meso‐wear). Enhancement in the fracture toughness from 2.9 to 10.7 MPam1/2 with reinforcement is attributed to the processing induced defects (such as dislocation, stacking fault etc.) in SiC and strong interfacial bonding of CNTs with TaC, as revealed by transmission electron microscopy (TEM). Delineation of the synergistic contribution of SiC and CNT reinforcement in TaC establishes the wear mechanism to be abrasion (via fretting test), brittle tensile cracking, and fracture (via micro‐scratch test).