RESUMEN
Aluminum alloy 7075 (Al 7075) with a T73 heat treatment is commonly used in aerospace applications due to exceptional specific strength properties. Challenges with manufacturing the material from the melt has previously limited the processing of Al 7075 via welding, casting, and additive manufacturing. Recent research has shown the capabilities of nanoparticle additives to control the solidification behavior of high-strength aluminum alloys, showcasing the first Al 7075 components processed via casting, welding, and AM. In this work, the properties of nanoparticle-enhanced aluminum 7075 are investigated on welded parts, overlays and through wire-based additive manufacturing. The hardness and tensile strength of the deposited materials were measured in the as-welded and T73 heat-treated conditions showing that the properties of Al 7075 T73 can be recovered in welded and layer-deposited parts. The work shows that Al 7075 now has the potential to be conventionally welded or additively manufactured from wire into high-strength, crack-free parts.
RESUMEN
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RESUMEN
The glass forming ability (GFA) of metallic glasses (MGs) is quantified by the critical cooling rate (R C). Despite its key role in MG research, experimental challenges have limited measured R C to a minute fraction of known glass formers. We present a combinatorial approach to directly measure R C for large compositional ranges. This is realized through the use of compositionally-graded alloy libraries, which were photo-thermally heated by scanning laser spike annealing of an absorbing layer, then melted and cooled at various rates. Coupled with X-ray diffraction mapping, GFA is determined from direct R C measurements. We exemplify this technique for the Au-Cu-Si system, where we identify Au56Cu27Si17 as the alloy with the highest GFA. In general, this method enables measurements of R C over large compositional areas, which is powerful for materials discovery and, when correlating with chemistry and other properties, for a deeper understanding of MG formation.
RESUMEN
Electrochemical devices such as fuel cells, electrolyzers, lithium-air batteries, and pseudocapacitors are expected to play a major role in energy conversion/storage in the near future. Here, it is demonstrated how desirable bulk metallic glass compositions can be obtained using a combinatorial approach and it is shown that these alloys can serve as a platform technology for a wide variety of electrochemical applications through several surface modification techniques.
