Al-based metal matrix composites reinforced with Al–Cu–Fe quasicrystalline particles: Strengthening by interfacial reaction

• Published in: Journal of alloys and compounds Vol. 607; pp. 274 - 279
• Main Authors: Ali, F., Scudino, S., Anwar, M.S., Shahid, R.N., Srivastava, V.C., Uhlenwinkel, V., Stoica, M., Vaughan, G., Eckert, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2014; Elsevier
• Subjects: Aluminum matrix composites (AMC); Applied sciences; Dispersion hardening metals; Exact sciences and technology; Interfacial reaction; Mechanical properties; Metals. Metallurgy; Phase transformation; Powder consolidation; Powder metallurgy. Composite materials; Production techniques; Quasicrystals; Mechanical properties; Phase transformation; Aluminum matrix composites (AMC); Interfacial reaction; Powder consolidation; Quasicrystals; Strengthening; Particle size; Heat treatment; Volume fraction; Metal matrix composite; X ray diffraction; Composite material; Dispersion strengthened metal; Hardening; Particle matrix interface; Yield strength; Quasicrystal; Interface reaction; Microstructure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2014.04.086

•Strength of composites is enhanced as the QC-to-ω phase transformation advances.•Yield strength increases from 195 to 400MPa with QC-to-ω interfacial reaction.•Reducing matrix ligament size explains most of the strengthening.•Improved interfacial bonding and nano ω phase explains divergence from model. The interfacial reaction between the Al matrix and the Al62.5Cu25Fe12.5 quasicrystalline (QC) reinforcing particles to form the Al7Cu2Fe ω-phase has been used to further enhance the strength of the Al/QC composites. The QC-to-ω phase transformation during heating was studied by in situ X-ray diffraction using a high-energy monochromatic synchrotron beam, which permits to follow the structural evolution and to correlate it with the mechanical properties of the composites. The mechanical behavior of these transformation-strengthened composites is remarkably improved as the QC-to-ω phase transformation progresses: the yield strength increases from 195MPa for the starting material reinforced exclusively with QC particles to 400MPa for the material where the QC-to-ω reaction is complete. The reduction of the matrix ligament size resulting from the increased volume fraction of the reinforcing phase during the transformation can account for most of the observed improvement in strength, whereas the additional strengthening can be ascribed to the possible presence of nanosized ω-phase particles as well as to the improved interfacial bonding between matrix and particles caused by the compressive stresses arising in the matrix.