Experimental Investigations on Microwave Sintered Alumina Graphene Composite Tool Inserts for Machining Of Hardened Steels

Abstract

ABSTRACT newline newlineThe selection of cutting tool material is an important factor for a successful newlinemachining operation. Cutting tool materials must withstand in extreme process conditions newlinelike high contact stresses and high temperature. Therefore, cutting tool materials must newlinepossess high hardness, high fracture toughness, chemical inertness, high thermal newlineconductivity and high thermal shock resistance. But in practice no single material exhibits newlineall of the desirable properties. The main classes of tool materials include high-speed newlinesteels (HSS), sintered tungsten carbides, cermets, ceramics, polycrystalline cubic boron newlinenitride and polycrystalline diamond. However, ceramic cutting tools are attracting the newlinemachining world in these years as they own more advantages than other cutting tools newlinematerials in certain areas. Ceramic materials are mainly based on aluminium oxide newline(Al2O3) and silicon nitride (Si3N4) newlineAluminium oxide, commonly referred to alumina, possesses tough interatomic newlinebonding giving rise to its desirable material characteristics and exists in several crystalline newlinephases, in which all phases will return to the most stable hexagonal and#945;-phase at elevated newlinetemperatures. Cutting tools made of pure alumina are used since the beginning of 20 newline newlinecentury for cutting low hardness steel but the low fracture toughness and low tensile newlinestrength of alumina is limiting it s application. In order to improve the properties of newlinealumina, several authors worked on alumina based composites by reinforcing pure newlinealumina with different varieties of particulates and processed through different fabrication newlineroutes. newline There are wide varieties of reinforcing materials and fabrication methods newlineavailable, but identification of appropriate fabrication route and reinforcing material is newlinealways been a difficult task which finally plays a vital role in fabricating a successful newlinecomposite material suitable to the desired machining application. newlineHence, the present work focused on the preparation of alumina-graphene newlinecomposite material which can be suitable as a