ABSTRACT: Brass alloys have extensive engineering uses as heat exchangers and condenser structures in salty water. Corrosion by pitting, cracking by stress corrosion, and dezincification of the brass in water was broadly considered. Brass dealloying or dezincification might be cheerfully detected with bare eyes since the alloy changed a ruddy color that is different from its yellowish color. In the previous period, various alloying elements have been used to reduce the dezincification and corrosion of brass alloys.
Current work is dedicated to investigating the effect of various amounts of zirconium additions (0.05,0.10, 0.15, and 0.20) wt.% to ?-brass alloy (Cu-Zn30) produced by die casting on mechanical and corrosion behavior.
Several tests were conducted in this research includes XRF and XRD for the specimens after casting and heat treatment, microstructure test for specimens before and after addition of Zr, dry wear test with and without the addition of Zr.
The results from optical microscope images show that Zr additions cause refinement of the original grains for ?-brass alloy (Cu-Zn 30).
Hardness test showed an increase of ?-brass alloy (Cu-Zn30) hardness with increasing Zr amount, the average hardness of the specimen without Zr addition was (102HV) while the average hardness of specimen with (0.20%wt Zr) addition increased to (185 HV).
The wear rate for ?-brass alloy (Cu-Zn30) specimen decreased after the addition of Zr (0.05,0.10, 0.15, and 0.20) wt.%. The wear rate of the ?-brass alloy (Cu-Zn30) was (12.3*10-6 cm3/ min.) while the wear rate of the specimen with (0.20%wt Zr) addition reduced to (5.66*10-6 cm3/ min) under load 30N for 30 minutes.
The ?-brass alloy (Cu-Zn 30) corrosion behavior with and without Zr has been studied by the electrochemical test in a salt solution (3.5% NaCl).
The corrosion rate for ?-brass alloy (Cu-Zn30) specimen decreased after addition of Zr (0.05 ,0.10, 0.15 and 0.20)wt.%. The corrosion rate of the ?-brass alloy (Cu- Zn30) was (203*10-4mpy) while the wear rate of the specimen with (0.20%wt Zr) addition was reduced to (2*10-4mpy) under the same conditions.

CONCLUSIONS: Zirconium addition to ?- brass Cu-Zn30 alloy with 0.05, 0.10, 0.15, and 0.20 wt.% via casting process enhanced significantly mechanical and corrosion properties as following:
• Hardness increased with increasing the amount of zirconium. Whereas wear and corrosion rate is decreased by increasing the amount of Zr.
• The hardness enhanced by(45%)when added 0.20 %wt.% Zr to ?- brass Cu-Zn30 alloy
• Wear rate is increased in general with increasing the applied load.
• The wear rate decreased by (54%) under conditions of 0.20 %wt. % Zr addition to ?- brass Cu-Zn30 alloy.
• The corrosion rate in 3.5%NaCl was reduced by (99% ) under addition of 0.20 %wt.% Zr to ?- brass Cu-Zn30 alloy.