Effect of ceramic particle addition on the foaming behavior, cell structure and mechanical properties of P/M AlSi7 foam

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 424; no. 1; pp. 290 - 299
• Main Authors: Esmaeelzadeh, S., Simchi, A., Lehmhus, D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.05.2006; Elsevier
• Subjects: AlSi7 metal foam; Applied sciences; Cell structure; Compressive properties; Dispersion hardening metals; Elasticity. Plasticity; Exact sciences and technology; Foam stability; Foamability; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Powder metallurgy. Composite materials; Production techniques; SiC particles; Cell structure; SiC particles; AlSi7 metal foam; Compressive properties; Foam stability; Foamability; Particle size; Structure stability; Mechanical properties; Aluminium alloy; Powder metallurgy; Compression test; Composite material; Dispersion strengthened metal; SiC particles: Foamability; Compressive stress; Metal foam; Powder compaction; Foam stability: Cell structure: Compressive properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.03.013

The effects of SiC addition on the foaming behavior and compressive properties of AlSi7 metal foams were studied. Elemental powders of Al, Si, SiC and TiH 2 were mixed, hot compacted and foamed at temperatures between 750 and 810 °C. The role of SiC volume fraction up to 10 vol.% and its particle size (3, 8 and 16 μm) was investigated. It was found that the foaming behavior of AlSi7 alloy, i.e. the maximum foam expansion and its stability, depends on the size and volume fraction of SiC particles. Increasing the amount of the ceramic particles and/or decreasing the particle size leads to less melt drainage whilst the cell structure becomes non-uniform. This is attributed to the effect of the ceramic particles on the viscosity of the aluminum melt and the cell wall thinning rate. Here, it was noticed that the effect of SiC addition is closely related to the temperature used for the foaming process. Also, a slight degradation in the mechanical properties under compressive load was observed. Better foamability with improved stability and proper mechanical properties were obtained in AlSi7–3 vol.% SiC (3 μm) precursor foamed at 810 °C.