Unveiling manganese effects on the hardness and electrical resistivity of Cu-20wt%Zn-xMn alloy

Abstract

This paper focuses on the effects of manganese contents on hardness and electrical resistivity of Cu-20wt%Zn-xMn alloy. Manganese was added in concentrations of (x: 0.1, 0.3, and 0.5wt%). The samples were produced by permanent die casting and machined to the required dimensions for the structural analysis and mechanical tests. Physical and mechanical properties studied were electrical resistivity and Brinell hardness respectively. Standard equipment was used to study the structure and calculate the hardness and electrical resistivity of the developed alloy. The results of the structural analysis showed that the control specimen consisted predominantly of coarse and needle-like α-phase of zinc in copper (Cu₃Zn). The samples doped with manganese consisted of refined dendrites of α-phase with patches of secondary phase. Physical and mechanical tests results indicated that addition of manganese to alpha brass increased the hardness and electrical resistivity respectively. The value increase recorded for electrical resistivity and Brinell hardness were from 0.74 x 10⁷Ωm to 1.32 x 10⁷Ωm and 124HB to 150HB respectively.