Heat-treatment studies on cast Ni-Mo-Cr-Fe-W-C multi-component alloy from scraps and electronic waste

Abstract

This study reports the synthesis and characterization of a sustainable Ni–Mo–Cr–Fe–W–C multi component superalloy incorporating electronic waste derived metals for advanced alloy development and circular economy applications. E-waste containing Cu, Sn, and Pb was added to a nickel-based superalloy matrix, followed by melting, casting, solution heat treatment at 1000 °C for 2 h, water quenching, and tempering. Microstructural, electrochemical, and tribological characterizations were conducted to determine the performance improvement. Scanning electron microscopy (SEM) connected to energy dispersive spectroscopy (EDS) showed that the heat treatment enhanced compositional homogenization, dissolution of some dendritic boundaries, and precipitation of second carbide, and subsequently promoted microstructural refinement. Strengthening and dispersion of carbide particles in the alloy was enhanced by the heat treatment too, resulting in an increment of Vickers hardness by 10.28%. The electrochemical tests indicated improvement in corrosion resistance via increase in open-circuit potential, decrease in corrosion current density, and increase in the charge transfer resistance. Tribological results showed a decrease in wear volume by 23.82% for heat-treated alloy, and a decrease in coefficient of friction when compared to the as-cast alloy. These enhancements were attributed to better mechanical integrity and surface stability of heat-treated alloy. The results confirm the possibility of using e-waste as the feedstock for high-performance engineering materials, sustainable metallurgy and waste-to-wealth alloy design technology.

The authors' abstract, as published at the source. Manufacturing Letters, 2026 · DOI ↗