Mechanical behavior of nickel + aluminum powder-reinforced epoxy composites

The mechanical behavior of composites containing micro-sized Ni particles and micro- or nano-sized Al particles, fabricated by casting/curing with epoxy, were studied to investigate their mechanical behavior for potential application as structural energetic materials. Reverse Taylor anvil-on-rod impact tests combined with high-speed digital photography provided information about the high-strain-rate transient deformation and failure response. The nano Al-containing composite exhibited a higher elastic modulus and static and dynamic compressive strengths than pure epoxy and micro Al-containing composite due to increased cross-link density, as revealed by dynamic mechanical analysis. Microstructural characterization of the cast composites revealed that micro-sized Ni and Al remained homogeneously and intimately mixed within the epoxy matrix. In contrast, the composites containing micro Ni and nano Al showed separation of the nano Al particles, effectively forming a nano Al + epoxy matrix surrounding the Ni particles and consequently altering the physical response and enhancing the mechanical properties of the composite.