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Lightweight metal matrix nanocomposites (MMNCs) (metal matrix with nanosized ceramic particles) can be of significance for automobile, aerospace, and numerous other applications. It would be advantageous to develop effective nanomanufacturing methods for fabrication of bulk components of aluminum-based MMNCs through solidification processing. However, it is extremely difficult to disperse nanosized ceramic particles uniformly in molten aluminum. In this paper, a high power ultrasonic probe is used to disperse nanosized SiC particles into molten aluminum alloy A356. Experimental results show that the ultrasonic cavitation based dispersion of nanoparticles in molten aluminum alloy is effective. The uniform nanoparticle dispersion in the Al alloy matrix resulted in significantly improved mechanical properties. To enhance the nanomanufacturing efficiency, various nanoparticle feeding techniques were explored and experimental results are presented.

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The Ni/SAPO-11 bifunctional catalyst for hydroisomerization of n-hexane was prepared via a novel synthesis method. It involved grinding of nickel source with amorphous precursors used for SAPO-11 followed by crystallization at 473 K for 24 h, thus avoiding the use of extra solvents in the synthesis. The highly dispersed nickel species and acid sites in the Ni/SAPO-11 bifunctional catalyst were instantaneouslyformed. The Ni/SAPO-11 catalyst contains framework nickel, nickel monoxide (NiO) and nickel aluminate spinel. The nickel monoxide with a size of 2-4 nm provides (de)hydrogenation function after reduction, while the framework nickel supplies more acid sites leading to an enhancedisomerization activity.The Ni/SAPO-11 catalyst shows a great synergeticeffect between the metallic nickel and acid sites with a high metal-to-acid sites ratio (C Ni /C A ) and close proximity. A single metallic nickel site is able to balance ca. 5 acid sites (C Ni /C A ≈0.19) over the Ni/SAPO-11 catalyst in n-hexane hydroisomerization.The high dispersion of nickel over the catalyst provides relatively excessive metal sites (C Ni /C A >0.19), leaving the rate limiting reaction to occur on the acid sites. The Ni/SAPO-11 catalyst exhibits comparable n-hexane conversion (71.2%) and iso-hexane yield (66.7%) to the classical Pt/SAPO-11 catalyst.With enhancing acidity, the Ni/SAPO-11 catalyst exhibits one of the highest iso-hexane yields reported in the n-hexane hydroisomerization, which render the new material as a promising candidate for the hydroisomerization catalysts.

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