MECHANICAL PROPERTY EVALUATION OF AGE HARDENED ALUMINIUM FOAM

Abstract

The outstanding properties of metal foams have attracted a great deal of interest from industry and the research community in recent years. Industries as diverse as bio-engineering, aerospace, automo tive design and manufacture, and jewell cry have been attracted by metal foams impact energy absorption, air and water permeability and unusual acoustic and insulating properties. In this present work aluminum foam with a closed cellular structure was prepared by a liquid melt foaming method. In the foaming process, the aluminum melt was mechanically agitated, and when, a suitable viscosity was achieved, a granular blowing agent was injected. Foam expansion ensued rapidly, and control of the melt viscosity was critical to achieve stable foam without slumping.. The quasi-static compressive properties of aluminum alloy foam as-received and thermally aged at various conditions were investigated. Microstructural analysis was carried out to identify the in-situ formed particles present and to corroborate the results with the stability and strength of the foam Plateau stress and Young's modulus and energy absorption capacity of foams deformed at lx 10"3 s"` strain rates are improved found to be improved after aging at 100°C for 1 hr. The typical aging characteristic of property improvement followed by decrease is noted for the sample aged at 300°C for various durations. Microstructural examination has revealed that grain boundary dissolution/coarsening occurs above NOT and the grain size is roughly the same for all temperatures except 550°C, wherein the Al2Cu interdendritic phase has dissolved. Clearly the microstructural development during aging influence the mechanical property of the foam.