Synthesis and characterisation of floatable magnesium alloy syntactic foams with hybridised cell morphology. (15th December 2018)

• Record Type: Journal Article
• Authors: Akinwekomi, Akeem Damilola; Tang, Chak-Yin; Tsui, Gary Chi-Pong; Law, Wing-Cheung; Chen, Ling; Yang, Xu-Sheng; Hamdi, Mohd
• Is Part Of: Materials & design. Volume 160(2018)
• Page Start: 591
• Page End: 600
• Publication Date: 2018-12-15
• Subjects: Magnesium alloy -- Powder metallurgy -- Microwave sintering -- Mechanical properties -- Syntactic foam -- Hybrid cells; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.10.004
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Powder metallurgy and rapid microwave (MW) sintering techniques were successfully applied to engineer a hybrid cell structure into magnesium alloy AZ61 syntactic foams. The hybrid cell structure, comprising open- and closed-cells, originated from leached carbamide granules and hollow microspheres of fly ash (HS), respectively. External MW susceptors accelerated the sintering process and greatly mitigated the formation of undesirable interfacial reactions. The cell hybridisation technique facilitated control over the density and strength of the syntactic foams. Accordingly, floatable syntactic foams with a density of about 0.79 g/cm 3 and compressive strength of 16 MPa were synthesised without recourse to any surface modification or chemically-induced superhydrophobicity. The processing techniques were capable of mitigating damage to the HS microspheres as confirmed by microstructural examinations. Furthermore, potential applications of the floatable syntactic foam sample, as a microboat and chemical release agent, were demonstrated by using ethanol as a propellant. AZ61 syntactic foams synthesised in this study exhibited low density and adequate strength, suggesting their applicability as alternative materials to polymer composite foams. Graphical abstract: Highlights: Magnesium alloy AZ61 syntactic foams with hybrid pore structure were fabricated via microwave sintering techniques. Floatable magnesium alloy AZ61 syntactic foam was realised with a density 0.79 g/cm 3 and adequate strength. The whole process of microwave sintering is within 20 minutes, minimizing the interfacial reactions and energy consumption. Potential applications as a floatable metallic microboat and chemical release agent were demonstrated.