Study on the Effect of Production Parameters and Raw Materials Used on the Mechanical Properties of Leaded Brass (CuZn40Pb2) Alloy

Abstract

Leaded brass alloys used progressively in many applications such as gas valves production owing to their excellent machinability, corrosion resistance and some other specifications. However, the production processes of these alloys involve some problems appearing in the last activities of production as a result of cumulative defects of previous production processes. Therefore, the current investigation studies the effect of process parameters during casting, hot extrusion and cold drawing production stages of CuZn40Pb2 leaded brass alloy on the mechanical properties. Starting with casting process, two types of charges were used. The first charge consists of 100% recycles while the second contains 30% of pure materials such as Cu, Zn and Pb in addition to the recycles. For each production stage, alloy hardness, micro-hardness, ultimate tensile strength and elongation were examined. The results illustrated that high hardness values are obtained during casting process due to some impurities such as iron and the effect of cooling rate through solidification. The hardness values decrease during extrusion process and then rise again by cold drawing for the charge of 30% pure materials. Micro-hardness values for the fractured tensile test samples appeared higher than others due to work hardening effect. The best mechanical properties as ultimate tensile strength of CuZn40Pb2 alloy products are appeared into cold forming samples with the 30% pure material added. Keywords

A Study of the Morphological Changes and the Growth Kinetics of the Oxides Formed by the High Temperature Oxidation of Cu-32.02% Zn-2.30% Pb Brass

“…Lead is often used as an alloying additive to ease the machining of brass and such brasses are referred to as leaded brasses 3 . Leaded brasses consist mostly of a two phase structure, namely the alpha and the beta phases, with the lead particles randomly distributed at the grain boundaries 4,5 . However, depending on the amount of zinc, brass as an alloy can exist with a single alpha-phase 6 .…”