The Role of Lead in the Machinability of Copper Alloys Used for Drinking Water Installations

Abstract The machinability of two copper alloys with lead: CuZn40Pb2 and CuSn5Zn5Pb2, was assessed. Turning tests were performed based on the selection of parameters that will result in the tool being worn out after 1 minute. Tool wear was assessed by observing dimensional and microstructural changes in the blade. When assessing machinability, power consumption, chip shape, changes in the surface layer and surface roughness were taken into account. The research aims to determine the custom machinability index of materials used in SANHA Polska. A publicly available index must be adapted to a given application, and such adaptation is often quite time-consuming. Therefore, a 1-minute test was carried out as a quick and cheap alternative to a large fleet of machines with various machining properties. The developed methodology and the results obtained are the basis for further research conducted as part of the implementation doctorate, the aim of which is to implement the production of well-machinable lead-free materials for drinking water installations, characterized by good solderability and corrosion resistance. As a result of the conducted research, the role of lead in the machining of copper alloys was identified, which is important due to European restrictions on the elimination of this element and its replacement in a way that allows for precise removal processing.