Using diluted master nanocomposites to achieve grain refinement and mechanical property enhancement in as-cast Al-9Mg

摘要

The grain refinement and mechanical property enhancement in ultrasonically prepared metal matrix nanocomposites (MMNCs) were studied in an Al-9Mg matrix with TiC_(0.7)N_(0.3) nanoparticle additions. Also, the ability to add pieces of previously prepared, higher concentration master MMNCs to melt for a lower final nanoparticle concentration MMNC was shown to be possible. Al-9Mg +1.5 vol.% TiC_(0.7)N_(0.3) nanocomposites were shown to have significantly reduced grain sizes and enhanced mechanical properties compared to the reference Al-9Mg samples. When pieces of the original Al-9Mg+1.5 vol.% TiC_(0.7)N_(0.3) were added to additional Al-9Mg melt for final nanoparticle concentrations of 0.2% and 0.5% by volume, much of the grain refinement and mechanical property enhancement was again observed. For comparison, samples were also made with a commercial Al-5Ti-1B grain refiner. The conventional Al-5Ti-lB grain refiner did achieve similar grain refinement; however this did not result in the same enhancement in strength and ductility. This "master nanocomposite" approach has great potential for bringing MMNC usage to the industrial stage.