Ultrasound-assisted drilling of copper and pre-alloyed powder metallurgy steels

摘要

Powder metallurgy (PM) steel components are generally considered 'difficult' to machine when compared with their wrought counterparts. Thus, efficient and cost effective machining strategies have to be devised. This paper summarises the results obtained by utilising ultrasounds to improve the machining behaviour of copper and sinter-hardenable PM steels. The effect of ultrasonic assisted drilling on tool life with and without admixed MnS is discussed as well. These results are compared to conventional machining methods and show that, for FC-0208 PM copper steels, tool life is increased by 180% and can be several thousand per cents higher if used in combination with admixed MnS. At the same time, the use of ultrasounds permitted to increase productivity by 86%, owing to the possibility of using higher feed rates. Similarly, for FLNC-4408 pre-alloyed PM steels, tool life was increased by 130% and productivity was 60% higher than when no ultrasounds were used.