Synthesis of FeSi-FeAl Composites from Separately Prepared FeSi and FeAl Alloys and Their Structure and Properties

• Published in: Materials Vol. 16; no. 24; p. 7685
• Main Authors: Novák, Pavel, Duda, Jiří, Průša, Filip, Skotnicová, Kateřina, Szurman, Ivo, Smetana, Bedřich
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-12-2023
• Subjects: Alloys; composite; Composite materials; Crystal lattices; Electric currents; Ferrosilicon; Ferrous alloys; Hardness; Intermetallic compounds; iron aluminide; Iron aluminides; Iron silicide; Mass ratios; Mechanical alloying; Mechanical properties; Metal industry; Oxidation; Particle size; Phases; Plasma sintering; Powder metallurgy; Raw materials; separate synthesis; Silicides; Silicon; Sintering; Sintering (powder metallurgy); Spark plasma sintering; Specialty steels; Temperature; Tool steels; Tribology; Tungsten alloys; Czech Republic; Germany; United States > US; separate synthesis; iron aluminide; iron silicide; composite; mechanical properties
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16247685

Composites consisting of iron aluminide and iron silicide phases were studied in this work. Powders of iron aluminide and iron silicide were prepared by mechanical alloying separately. Subsequently, they were blended in three different proportions and sintered by the SPS method under various conditions. After sintering, the composites are composed of FeAl and amounts of other silicides (Fe
Si
and Fe
Si). Ternary Fe-Al-Si phases were not determined, even though their presence was predicted by DFT calculations. This disagreement was explained by steric factors, i.e., by differences in the space lattice of the present phases. Hardness and tribological properties were measured on composites with various weight ratios of iron aluminide and iron silicide. The results show that sintered silicides with the matrix composed of iron aluminide reach comparable hardness to tool steels. The composites with higher mass ratios of iron aluminide than silicide have higher hardness and better tribological properties.