Multi-Functional Metal/Ceramic Hybrid Composites for Structural Applications

Abstract

Some ceramic based hybrid composites with metallic particles have excellent mechanical properties. In particular, metal/ceramic nanocomposites has high mechanical strength and improved fracture toughness. Magnetized hybrid composites can be produced by dispersing Fe, Co or Ni nanoparticle in the structural ceramics. Crack healing of metal/ceramic hybrid composites was investigated for structural applications. Cracks of nanoNi/Al2O3 introduced by the Vickers indentation of 49 N could be repaired completely, for example, by air oxidation at 1200°C for 6 h. Even larger cracks introduced by 490 N indentation was healed up to a comparable level of mechanical strength by oxidation at 1200°C for 24 h in air. Outward diffusion of cations during high-temperature oxidation would cause crack repair by filling with an oxidation product. Faster crack disappearance, 900°C for 1 h, was realized on Mo/Al2O3. Surface crack healing effectiveness promoted by outward diffusion of cations is potentially applied into various Al2O3 based hybrid material systems, as well as excellent mechanical properties.