Reinforcement of Al–Fe–Ni alloys with the in situ formation of composite materials

• Published in: Journal of alloys and compounds 2009-08, Vol.483 (1), p.178-181
• Main Authors: Vourlias, G., Pistofidis, N., Pavlidou, E., Stergioudis, G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Dispersion hardening metals; Exact sciences and technology; Materials science; Metal matrix composites; Metals. Metallurgy; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructured materials; Physics; Powder metallurgy. Composite materials; Production techniques; Scanning electron microscopy; Transmission electron microscopy; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.07.173

One of the most effective methods for the improvement of the mechanical properties of metals is their reinforcement with non-metallic materials. In the present work powder of K 2TiF 6 and KBF 4 was added in an Al–Fe–Ni alloy while the alloy was in liquid form at 1060 °C with a 5 wt.% mixture of powders and with simultaneous stirring for 30 min. The liquid was squeeze-casted at 150 bar. The as-cast specimens were examined with electron microscopy and X-ray diffraction. SEM analysis revealed that the as-formed material is composed by needle-like crystallites along with a dentritic form and an interdendritic phase. The composition of the needle-like crystallites may presumably be expressed by the formula (Fe-Ni)Al 3. The rest of the matrix consists of almost pure Al grown dentritically, while the interdendritic phase contains Fe and Ni dissolved in Al. EDS analysis also proved the existence of spots with high Ti concentration, which probably refer to the Ti–B compounds. Finally TEM verified the presence of nanocrystals in the matrix.