Comparative study of the parameters influencing the machinability of leaded brasses

One of the main applications of brasses is the manufacture of fluid carrying systems. The shape of the final product is usually made by means of machining the rolled or extruded standard bars, so that effective and low cost machining operations are required. Leaded brasses are extensively used when a good machinability is required.Two leaded brasses bars (CuZn39Pb3 alloy) with the same geometry but with different behaviour in saw cutting operations have been characterized in this work. Chemical composition, mechanical and microstructural properties have been studied in order to clarify the observed differences during saw cutting machining.Significant differences have been found with respect to the size and distribution of lead globules and phase volume fractions (α + β′), that have been explained due to the existence of different solidification and cooling patterns in both products; being the lead distribution the most important characteristic relative to the leaded brass cutting performance.