Microstructure,mechanical properties and machinability of Cu–Zn–Mg and Cu–Zn–Sb brass alloys

Lead-free alloys have attracted great attentions recently due to the toxic nature of lead for the human body. In this study, low amounts of Mg and Sb were added to the Cu65–Zn35 brass and microstructure, mechanical properties and machinability of samples were compared to Cu65–Zn35 brass. Both Mg and Sb led to the promotion of β′ phase as well as the formation of new ternary copper rich intermetallic particles. It was found that these particles had a significant role in the reduction of the ultimate tensile strength, toughness, work hardening and elongation while increasing the hardness of samples. Results of machinability evaluation of samples showed that the cutting forces were decreased significantly and morphology of chips were improved compared to Cu65–Zn35 brass sample.