Study on tool wear estimation for small diameter ball end mill milling

Ceramics are non-conductive materials, consequently, they cannot be machined directly by any electrical means. If these ceramics contain some small fractions of conductive components, e.g., as pollutant or as glue materials, they perform a certain, really low level, local and accidental flash of some conductivity. The reported research was performed on this border of science, with ceramics that are below the practical and also below the state-of-the-art conductivity level for electrical machining. Even so, micro-Electric Discharge Machining (micro-EDM) for cermaics was developed with varying and many times uncertain success. The paper describes the required, extended measuring system of a micro discharge milling machine equipped with a linear encoder, voltage, and current sensors. With the help of the installed measuring system, the ceramic discharge milling of the Al2O3–TiC mixture was tested, in particular, the process stability, the geometric transient zones and the edges of the machined grooves.