Performance for End Mills Made of Different Tool Materials with Regards to Tool Life and Stability

Abstract

End milling operations are mostly used to machine parts of complicated shape in aerospace and turbomachine industries, where machine cost/hour is quite high for Multi-axes NC machines. This requires higher cutting speeds to economically utilize the machine tools and very often use of HSS cutters limits the metal removal rate due to low cutting speeds of HSS tools. Futhermore, cutting tool deflection and forced vibration due to impact farces in end milling are severe limitations, often resulting in surface and form imperfections. End milling cutters are made of either conventional and PM high speed steel or of Solid Cemented Carbides. Conventional HSS cutters are today widely used for all types of end milling operations. But it has been found in this study that the use of solid CC end mills attenuates both the tool vibrations and static deflection and at the same time allows a higher metal removal rate. Tool life and stability study of end milling cutters of two different tool materials. High Speed Steel and Cemented Carbide has been carried out showing that solid CC end milling cutters with diameter approximately above 12 mm can economically be utilized for machining tougher work materials. Although the solid CC end mills with diameter below 8 mm may have a better performance with regards to tool bending and tool vibrations, they are very often susceptible to cutting edge and cutting shaft breakage.