|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Morphological Development of Quasicrystals in Powder-processed Icosahedral-phase-strengthened Aluminum Alloys
||Hannah Leonard, Sarshad Rommel, Thomas Watson, Venkat Vedula, Mark Aindow
|On-Site Speaker (Planned)
Recently, we have developed an Al-Cr-Mn-Co-Zr alloy that exhibits a nano-composite FCC Al plus I-phase microstructure in gas-atomized powder. This microstructure is retained during consolidation of the powder to form bulk material or cold-sprayed coatings, and the materials exhibit a remarkable combination of mechanical properties and pitting corrosion resistance. Here we report a study on the morphological development in a series of three more dilute Al-Cr-Mn-Co-Zr alloys. It is shown that the powders contain the same phases as the original alloy, but there are three distinct I-phase microstructures in the powder particles: equi-axed dispersoids, radial growths and surface decoration. The dominant microstructures are found to vary with particle size (and hence cooling rate) and alloy composition. These microstructures are retained in the powders after consolidation giving local microstructural zones with the corresponding I-phase morphology. The consequences of these effects for the mechanical behavior of the alloys are discussed.
||Planned: Supplemental Proceedings volume