Influence of cutting edge micro-geometry in micro-milling of copper alloys with reduced lead content

Especially copper-zinc alloys (CuZn) with good machining properties are used for electrical components and fittings. By using copper alloys with lead content of 1 % < Pb < 3 % an improved chip breakage can be achieved. Legal regulations require the reduction of lead and demand further knowledge about the effect of the material properties in interaction with the used micro-milling tools. In this contribution the cutting conditions of copper as well as four copper alloys were examined. The results show considerable differences in the resultant surface roughness and burr formation. Furthermore, the influence of two different tool geometries and variied cutting edge micro-geometries were investigated while machining CuZn21Si3P. Thereby, tools with increased cutting edge radii rv showed increased active forces Fa, burr height h0 and decreased surface roughness.