Microstructure, Hardness, and Corrosion Resistance Analysis of Cu-40Zn-xSn Prepared by Gravity Die Casting Process
Imam Basori, Fachrul Rozy, Agung Premono

Department of Mechanical Engineering, Faculty of Enginnering, Universitas Negeri Jakarta

Abstract

Brass is an alloy consisting of a mixture of copper and zinc. In this study, the type of brass used is naval brass with a Cu content of 60% and Zn of 40%. Naval brass has good strength and good corrosion resistance. Naval brass applications are usually used in the manufacture of marine equipment such as ship propellers. However, naval brass is included in copper alloys that easily react, dissolve, and corrode in seawater conditions. Corrosion that occurs in brass alloys is called dezincification. Dezincification can be avoided by adding elements, one of which can be used is tin (Sn). This study was conducted to determine the effect of adding tin (Sn) on the microstructure, hardness, and corrosion resistance of Cu-40Zn brass alloys. For sample preparation, the gravity die casting process was carried out with variations in the addition of Sn elements, starting from 0 wt.% Sn, 0.5 wt.% Sn, 1 wt.% Sn, and 1.5 wt.% Sn. After that, the casting results will be homogenized at a temperature of 800&#8451- for 2 hours. After being homogenized, the samples were cut for several tests, namely composition testing, microstructure observation, hardness testing, and corrosion testing. From the results of the research conducted, the addition of Sn elements can affect the microstructure, because the addition of Sn elements encourages the formation of the &#946- phase. The results of the hardness test showed an increase in the hardness value along with the addition of Sn elements, namely 134.22 VHN, 151.64 VHN, and 162.1 VHN. Further, it can be concluded that the addition of Sn elements can increase the hardness value of brass alloys. In the corrosion test, the corrosion rate values were obtained at 0.3354 mmpy, 0.1956 mmpy, and 0.2362 mmpy along with the addition of Sn elements. Finally, it can be concluded that the addition of Sn elements affects the corrosion resistance of brass alloys.

Keywords: Brass, Dezincification, Microstructure, Hardness, Corrosion Resistance

Topic: Material Physics