Manufacturing Technology 2024, 24(2):235-240

Microstructure and Properties of Natural Alloy Prepared by Aluminothermic Reduction of Deep-Sea Nodules and Processed by Rapid Solidification

Alena Michalcová ORCID..., Matouš Orlíček ORCID..., Pavel Novák ORCID...

Department of Metals and Corrosion Engineering, University of Chemistry and Technology in Prague. Technická 5, 166 28 Prague 6. Czech Republic

This paper explores the investigation of a natural alloy processed using the rapid solidification tech-nique. The study involves the reduction of manganese nodules through aluminothermy with a 20 wt. % excess of aluminum, followed by further processing of the resulting alloy using the melt-spinning process. The obtained melt-spun ribbons were subjected to a comprehensive analysis, including X-ray diffraction, scanning electron microscopy for microstructure observation, and EDS analysis for local chemical composition. The research unveiled that the rapidly solidified ribbons consist of several key phases, including β-Mn, the Heusler phase Mn2FeSi, and an intermetallic phase (Cu,Mn)3(Al,Si). Im-portantly, the phase composition exhibited notable differences from that of the as-reduced alloy, with a reduced number of phases in the rapidly solidified ribbons. Notably, the phase composition re-mained stable even after annealing, demonstrating the robustness of the rapidly solidified material. Impressively, the material exhibited a remarkable hardness of approximately 800 HV 0.1, even after 100 hours of annealing at temperatures of 500 and 750°C.

Keywords: Manganese Alloy, Manganese Nodules, Natural Alloy, Rapid Solidification, Melt-spinning

Grants and funding:

This research was funded by the Czech Science Foundation (project No. 20-15217S)

Received: December 2, 2023; Revised: January 22, 2024; Accepted: March 13, 2024; Prepublished online: March 20, 2024; Published: April 30, 2024  Show citation