Production and Functional Properties of Graded Al-Based Syntactic Metal Foams

Abstract

As cellular materials are gaining more ground in the automotive, airplane, and railway industries, the demand for functionally graded metal foams has appeared. In the case of syntactic metal foams, by changing the distribution of the filler material, the properties of the foams can be precisely adjusted according to the desired area of application. Several kinds of graded aluminum matrix syntactic foams (GMSFs) were fabricated with lightweight expanded clay aggregate particles and ceramic hollow spheres as filler materials. Their mechanical properties were observed by modal analysis and compression tests, supplemented with an accurate density determination by computer tomography measurements. The compressive properties were set up on a large scale by adjusting the density by adding specific amounts of Al particles to the filler. Based on the modal analysis results, simple averaging the density of GMSFs produces an inaccurate result in mode shapes and material parameters, so the varying density distributions should be taken into account. By simply varying the distribution of the filler material, we can modify the effective material properties of metal foams to better fit industrial requirements.