Structural and mechanical properties of Ni60Nb40 amorphous alloy particle reinforced Al-based composites produced by microwave-assisted rapid sintering

Abstract

Novel Al-composites were produced by reinforcing pure Al with varying volume fractions of Ni60Nb40 amorphous alloy powders (Vp) using microwave-assisted two-directional rapid sintering, and subsequent hot extrusion. The composites were investigated for their structural and mechanical properties. Structural analyses reveal: (a) uniform distribution of reinforcement, (b) absence of interfacial products, (c) structural dilatation and change in aspect ratio of reinforcement at 25% Vp and (d) retention of amorphous structure of reinforcement at all Vp.Electrical resistivity of composites increases with increase in Vp. Microhardness and compressive strength properties increase remarkably with Vp (~130% and ~100% respectively, at 25% Vp). The composites do not fracture under compressive loading even at ~50% strain. Tensile tests show a significant enhancement in strength of ~60% at 25% Vp. The report on the tensile behavior of amorphous alloy/glass-reinforced composites is the first of its kind. The mechanical properties of the developed composites have been compared with those of the existing composites and with the theoretical estimates. The mechanical behavior is discussed based on processing-structure-property correlation. The results highlight the potential of amorphous/glassy alloys as better alternative reinforcements to produce high performance composites. They also show microwave sintering as an effective processing method to produce such composites. © 2013 Elsevier B.V.