ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Impact of Si and/or Cr on the characteristics of FeNiMn-based alloys produced by powder metallurgy

Shimaa A. Abolkassem, Aliaa Abdelfatah, Omayma A. Elkady, and Lamiaa Z. Mohamed

Powder Technology Department, Manufacturing Technology Institute, Central Metallurgical R and D Institute, Helwan, Egypt

E-mail: lamiaa.zaky@cu.edu.eg

Received: 24 May 2025  Accepted: 5 October 2025

Abstract:

Equiatomic FeNiMnSi, FeNiMnCr, and FeNiMnSiCr alloys were fabricated using the powder metallurgy technique. Thermodynamic calculations classified FeNiMnSi and FeNiMnCr as medium-entropy alloys, while FeNiMnSiCr was identified as a high-entropy alloy (HEA). Among these, FeNiMnSiCr exhibited the highest relative density and the most favorable thermodynamic stability (Ω = 5.57, ∆S_mix = 13.38 kJ/mol K). X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy confirmed a multiphase microstructure with well-dispersed elements. Mechanical testing revealed that FeNiMnSi and FeNiMnSiCr exhibited higher hardness compared with FeNiMnCr. In corrosion studies, FeNiMnSiCr demonstrated the lowest corrosion rates of 0.41 mm/y in 1 M HCl, 0.11 mm/y in 1 M HNO₃, and 0.46 mm/y in 1 M H₂SO₄, confirming its superior chemical resistance. Surface examinations further revealed reduced micro-galvanic attack compared with FeNiMnSi and FeNiMnCr. Overall, these results highlight FeNiMnSiCr as a promising HEA with a balanced combination of mechanical strength and corrosion resistance.

Keywords: Medium entropy alloys; High entropy alloys; Powder metallurgy; Corrosion behavior; Microstructure

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04427-4

Chemical Papers 80 (1) 769–787 (2026)