A review of ultra high speed milling of hardened steels

The term 'High Speed Machining' has been used for many years to describe end milling with small diameter tools at high rotational speeds, typically 10 000-100 000 rpm. The process was first applied in the aerospace industry for the machining of light alloys, notably aluminium. In recent years, however, the mould and die industry has begun to use the technology for the production of components, including those manufactured from hardened tool steels. This has only been made possible by advances in machine tools, cutting tools and CAD/CAM systems. Promising results have been demonstrated when milling a range of hardened tool steels using machining centres equipped with high speed spindles and cutting tools manufactured from cemented tungsten carbide, cermet, conventional ceramics and polycrystalline cubic boron nitride. The paper reviews HSM machinability work over the last decade and includes tool life, workpiece surface finish/dimensional accuracy and cost data. Sample components are illustrated and machining parameters correlated against workpiece hardness. (C) 1997 Elsevier Science S.A.