High Strain Rate Tensile and Compressive Testing and Performance of Mesoporous Invar (FeNi36) Matrix Syntactic Foams Produced by Feedstock Extrusion

The present study investigates the high strain rate behavior of mesoporous metal matrix syntactic foams focusing on the dependence of compressive and tensile properties on strain rate. The strain rate range, covered both in compression and tension, extends from quasi-static conditions or 10(-3)s(-1) to 10(3)s(-1). Syntactic foams based on commercial high strength hollow glass microspheres and Invar (FeNi36) matrix are produced by means of feedstock extrusion and subsequent sintering. Levels of glass microsphere addition examined are 5 and 10wt%, respectively, corresponding to approximately 40 and 60 vol% of microspheres in the initial mix prior to sintering, and considering the metal and filler fraction only. Reference samples containing no microsphere addition have been included in the study. Mechanical testing is accompanied by metallographic examinations.