(in lingua inglese)
Free cutting brass as specified by the ASTM B16 has different microstructures for the different composition of the major alloying elements. This affects the material properties, particularly, hardness. The material has homogenous alpha phase at zinc content less than 35 wt.% and the heterogeneous alpha + beta above 35 wt.%. The presence of b-beta phase makes the material more brittle and causes the material to crack during the plastic deformation/cold working. The cracks formed will propagate through the harder b phase in the microstructure.