Novel design and composition optimization of self-lubricating functionally graded cemented tungsten carbide cutting tool material for dry machining

The functionally graded cemented tungsten carbide (FGCC) is a suitable material choice for cutting tool applications due to balanced hardness and fracture toughness. The presence of cobalt and CaF2 composition gradient in FGCC may enhance mechanical as well as antifriction properties. Therefore, structural design of self-lubricating FGCC was proposed using Power law composition gradient model and thermal residual stresses (TRSs) as a key parameter. Wherein, S. Suresh and A. Mortensen model was adopted for estimation of TRS, and optimum composition gradient was identified at Power law exponent n = 2. The designed material displayed compressive and tensile TRS at surface and core respectively; subsequently fabricated by spark plasma sintering and characterized via scanning electron microscope (SEM), indentation method. The agreement between experimental and analytical values of TRS demonstrated the effectiveness of intended design model in the composition optimization of self-lubricating FGCC. This work will be helpful in implementation of dry machining for clean and green manufacturing.