Journal of Materials Science, Vol.43, No.23-24, 7474-7480, 2008
Novel microstructures from severely deformed Al-Ti alloys created by chip formation in machining
We present some consequences of Severe Plastic Deformation (SPD) of Al-Ti alloys by chip formation in machining that can enable opportunities for creating novel microstructures. Chips cut from Al-6wt%Ti are composed of a refined dispersion of the fragmented remains of a hitherto coarse Al3Ti embedded in a nanostructured matrix. This multi-phase nanostructured chip material demonstrates considerable resistance to coarsening owing to the thermally stable dispersion of ultra-fine Al3Ti dispersions and thus has promise in structural alloy applications. Furthermore, the Al-Ti machining chips are shown to possess excellent grain refining characteristics, leading to microstructurally refined and homogeneous Al alloy castings. This realization enables a low-cost route for enhancing the efficiency of the grain refiner master alloy systems by exploiting SPD during chip formation.