Papers by Author: Jia Jun Gu

Abstract: The microstructures and tensile performance of B4C particulate reinforced 2024 Al alloy matrix composites produced by mechanical alloying and common blending techniques were investigated. The results showed that mechanical alloying was an effective way to fabricate the particulate reinforced Al matrix composites over common blending. The samples by different mixing techniques exhibited a clean and chemical products free interface. Tensile strength and elastic modulus of the composites was higher than that of the based alloy at the expense of ductility. The composites by common blending exhibited a more ductile fracture surface in contrast to specimen by mechanical alloying.

Abstract: The elevated temperature deformation and fracture behavior of an 10vol%B4CP/7039 aluminum matrix composite plate was investigated by uniaxial tensile tests at temperatures ranging from573 to 773 K and at initial strain rates from 1x10-1 to 1x10-4s-1.The strain rate sensitivity exponent was found to be approximately 0.1-0.15 which was below that of a superplastic material. A maximum elongation of 116% was obtained at an initial strain rate of 10-1 s-1 and at a temperature of 773 K.

Abstract: Morph-genetic synthesis, a preparation method using bio-structures as templates for fabricating micro-cellular materials, has attracted a considerable interest in recent years. In this report, we summarize our obtained results on synthesizing oxides and carbides based on wood templates (for TiC and SiC) and cotton templates (for Al2O3, SnO2 and SiC), respectively. The final products are observed to be faithfully retaining the micro-morphologies of their original natural counterparts, with the template bodies absolutely or partially replaced by the chemically synthesized compounds. These results suggest a new and handy way to fabricate materials with various microstructures, with deliberately choosing desired bio-structures from billions of different species as templates. Moreover, results on Al infiltrated wood templates, as a composite system, are also presented.