Abstract
A systematic approach is the focus of the current work in order to design and develop ceramic composites for cutting tool inserts with a balanced combination of structural and thermal properties together with enhanced antifriction characteristics. In the material design stage, various combinations of ceramic materials and inclusions with optimum self-lubricating attributes are selected based on predictions of mechanical and thermal properties using in-house built codes. A mean-field homogenization scheme is used to predict the constitutive behavior while J-integral based fracture toughness model is used to predict the effective fracture toughness of the ceramic composites. An effective medium approximation is used to predict the potential optimum thermal properties. The current strategy incorporates thermal and structural properties of composites as a constraint on the design process together with self-lubrication property. Among various metallic and carbon-based fillers, silicon carbide (SiC) together with titanium oxide (TiO2) and graphite are found the most suitable candidate fillers in alumina (Al2O3) matrix to produce cutting inserts with best combinations of thermal, structural and tribological properties. As a validation, various combinations of Al2O3-SiC-TiO2 and Al2O3-SiC-TiO2 composites are developed in line with the designed range of filler size and volume fraction using Spark Plasma Sintering (SPS) process to complement the material design.
