Elements of the Machining Process
Fundamental to the machining process, is the metal-cutting operation, which involves extensive plastic deformation of the work piece ahead of the tool tip, high temperatures, and severe frictional conditions at the interfaces of the tool, chip, and work piece. This article explains that the basic mechanism of chip formation is shear deformation, which is controlled by work material properties such as yield strength, shear strength, friction behavior, hardness, and ductility. It describes various chip types, as well as the cutting parameters that influence chip formation. It also demonstrates how the service life of cutting tools is determined by a number of wear processes, including tool wear, machining parameters, and tool force and power requirements. It concludes by presenting a comprehensive collection of formulas for turning, milling, drilling, and broaching, and its average unit power requirement.