Tribo-mechanical characterization of Cu-Cr-Zr ternary alloy aimed at fin-tube resistance welding electrode material

Abstract

Purpose Low performance life and increased machine downtime due to wear of resistance welding copper electrode is of major concern in fin–tube resistance welding in waste heat recovery boilers. The purpose of this study is to investigate an alternative material with good wear resistance to replace the currently utilized C11000 electrolytic tough pitch (ETP) copper electrode. Design/methodology/approach In this study, a Cu-Cr-Zr ternary alloy was developed for fin-to-tube welding electrode by melting commercial grade electrolytic copper (99.9% purity) plates, chips of chromium, powder of zirconium at 1100°–1300°C, followed by hot forging and precipitation hardening at 450°–550°C to attain appropriate grain flow. Microstructures of Cu-Cr-Zr alloys were analysed using scanning electron microscopy coupled with energy-dispersive backscatter electron spectrometry. Findings Wear performance of Cu-Cr-Zr and C11000 ETP Cu was evaluated using pin-on-disc set-up with Taguchi’s L8 orthogonal array. Ranking of the parameters was done, and it was observed that the material and temperature play a very significant role in controlling the wear of an electrode. Practical implications Rate of fin–tube resistance welding was increased by 26% with Cu-Cr-Zr alloy. Further investigation on effect of plasma on the metallurgical characteristics of Cu-Cr-Zr is recommended. Originality/value Tribo-mechanical performance of newly developed Cu-Cr-Zr ternary alloy was compared with C11000 ETP copper. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2023-0092/