APPLICATION BASED MATERIAL DESIGN AND DEVELOPMENT APPROACH FOR CUTTING TOOL INSERTS

Cutting tool inserts made from various nanocomposites have received special interest in recent years. They have demonstrated increased performance, reliability and lifetime with respect to monolithic cutting tool materials. However, a successful approach to the development of tailored cutting tool materials requires the development of innovative concepts at each step of manufacturing, from the material design, synthesis of composite powders, to their processing and sintering. The ideal requirements of a satisfactory cutting tool can easily be defined, but it is more difficult to specify a tool material that meets all these requirements over a wide range of cutting conditions. This proposed work aims on computational design approach to be applied in development of reinforced ceramic (based on oxide and non-oxide nitrides and carbides) cutting tool inserts with tailored structural and thermal properties for high-speed machining applications with enhanced structural and thermal performance. Some of the potential reinforcements/fillers used are carbides or carbonitrides (TiC, SiC, Ti(C, N)), polycrystalline cubic boron nitride (PcBN), and grapheme platelets that could improve toughness and thermal conductivity of ceramic based cutting tool inserts. A mean field homogenization and effective medium approximation (EMA) using an in-house code will be used for predicting potential optimum structural and thermal properties for cutting tool materials by considering the effect of reinforcement type, volume, size and thermal and structural interface in the ceramic matrix. The primary goal for designing such ceramic-based cutting tool material is to have enhanced structural and thermal properties needed for high speed machining applications. Staring with number of potential fillers/reinforcements at the material design stage, the most suitable candidate fillers that could enhance the thermal and structural performance of the ceramic-based cutting tool inserts will be identified. To complement the computational design, ceramic disc shaped inserts with designed range of reinforcements volume fractions and sizes will be developed using spark plasma sintering process and desired structural and thermal properties will be measured for model verification. Microstructural analysis and phase characterization of the sintered samples will also be conducted using Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) to study the morphology of the developed inserts and to relate them with the obtained properties. The proposed design and development strategy is expected to provide a useful guideline for the tool insert manufacturers in developing new cutting tool grades by selecting appropriate matrix and reinforcement for high speed machining applications.