Abstract

Silicon carbide in the form of a foam network was vacuum infiltrated with aluminum alloy A356 to produce a new Interpenetrating Composite material. The foam, once infiltrated with a second phase transforms into a composite where two distinct, continuous, three-dimensional network structures are formed. The advantage of this metal matrix composite is its high strength-to-weight ratio for use in lightweight applications such as electronic packaging materials. The electroless nickel coating and vacuum infiltration procedures are developed. Materials characterization of the composite is evaluated by microstructural and compositional analysis, and density, porosity, and nano-indentation measurements. Selected experimental mechanical and thermal property measurements are performed to understand its properties and compare against theoretical models. Results show the final composite to have lower density than conventional electronic base plate packaging materials with low porosity. The composite has an increased Young's modulus and flexural strength to that of the unreinforced alloy and comparable impact toughness to composites with 50–70 vol% SiC particles but with only 12 vol% SiC. The fracture surface of the matrix illustrates conventional fibrous fracture and brittle cleavage whilst the reinforcement struts show signs of layer de-bonding from their SiC layered structure.