Understanding the Co-precipitation Mechanisms of Al3(Sc, Zr) with Strengthening Phases in Al–Cu–Li Model Alloys
The addition of scandium (Sc) is known to be beneficial to the properties of aluminium alloys. Sc has a significant impact on the strength, especially when combined with zirconium (Zr) where nano-size Al3(Sc, Zr) dispersoids are formed. However, to date the extraction of Sc from its oxide has been too expensive to promote its use on the industrial scale. New extraction methods have made the process more cost-effective. So far, there has been only limited research done concerning the effect of Sc in Al–Cu–Li alloys. Interaction between the Al3(Sc, Zr) dispersoids and other precipitate phases containing copper (Cu) and/or lithium (Li) have been rarely studied. In this study, the impact of Sc and Zr on precipitation and further the properties of Al–Cu–Li alloys is investigated. Mechanical properties were examined by quasi-static tensile tests. Using TEM, the morphology and size of dispersoids and precipitates were examined.
KeywordsScandium Texture Precipitation Aluminium alloy
The authors would like to acknowledge Clean TeQ for providing in-kind Al-Sc master alloys. Dave Gray is warmly thanked for casting the alloys used in this project. Deakin University’s Advanced Characterization Facility is acknowledged for use of the Jeol 2100F transmission electron microscope.
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