Investigation of tool geometry, coating and coolant in micro milling of single crystal Nickel-based superalloy Rene N5

Single crystal (SX) nickel based superalloys have particular high temperature mechanical properties, oxidation and corrosion resistance. Therefore, these alloys are predestined for high temperature applications like high pressure turbine blades (HPT) of aero or industrial gas engines. This paper presents the viability of micro milling Rene N5. The influence of tool geometry, coating and coolant on the surface quality and tool wear was investigated. One result of the analysis was that a coated tool with a minimum quantity of lubrication (MQL) performed better in comparison with uncoated tools and emulsion coolant. The data obtained can be used to rank the coatings and coolants studied and in some cases predict the relative lifetime of a coated tool.