Optimization and Characterization of Manganese Coating on Cu-Cr-Zr-Ti Alloy

Abstract

In this study, the deposition of Manganese (Mn) on Cu-Cr-Zr-Ti alloy was carried out using electro plating route. The purpose of this coating is to join copper alloys utilizing eutectic reaction between Cu and deposited Mn. Mn coating through electro deposition is difficult due to very high electronegativity. Two different bath compositions have been studied, with and without the addition of sodium selenate (Na2SeO4), where base composition remains same (MnSO4& (NH4)2SO4).The influence of the bath composition and deposition parameters such as pH, current density, time on the deposition rate of Mn coating was studied. Higher deposition rate of Mn was obtained with lower pH and higher current density (~6 amps/dm2). Time of deposition was optimized to obtain varying thickness, ranging from 10 to 30 microns. Detailed characterization was carried on the Mn coated samples using OM, SEM-EDS and AFM. XRD phase analysis on the coated surface ensures the presence of α-Mn at room temperature. Subsequently, DSC analysis was carried out on the Cu alloy/Mn deposit pair to assess the brazeability temperature window.