Some aluminum-rich amorphous alloys (glasses) crystallize (devitrify) into nanostructured composites that exhibit greatly enhanced mechanical properties of potential technological significance to aerospace and other applications. However, to date production of aluminum-rich glasses has required melt spinning at rapid quench rates. For the partially crystallized aluminum-based nanocomposites to become economically viable the precursor glasses must become more stable, such that they may be obtained as bulk glasses by standard melt-cooling methods. A group of aluminum-rare-earth-transition-metal (Al-RE-TM) glasses, rich in Al, is reported herein. Very small amounts (0.5 – 2 atomic %) of Ti, Zr, or V microadditives produce significant enhancements in glass formability and stability in the parent alloy Al88Y7Fe5. The new microalloy glasses all exhibit distinct glass transitions, enhanced thermal stability towards primary crystallization, and decreased sensitivity to oxygen contamination. The glass-formability parameters Trg and g for these materials are impressive, and are approaching the range of other bulk glass formers. The role of the microadditives appears to be the formation of local structural order in the glasses that disfavors crystallization.
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