A multi-process approach towards the development of novel Mg alloys

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For decades, technological advancements have been driven by the progress in materials science. For example, the substitution of iron components in automobiles with lighter aluminum components during the 1970's and 80's resulted in an immediate performance and fuel economy enhancement. In light of the global climatic challenges, governments internationally are mandating automakers to drastically decrease greenhouse gas emissions and improve fuel economy of vehicles, otherwise face economic penalties. It is generally accepted that the required improvement is achievable either by vehicle hybridization, or by vehicle weight reduction. Both approaches face challenges: 1) Hybridization is costly and adds weight to vehicles, and 2) Existing manufacturing processes for lightweight alloys are approaching technological limits and further advancements are costly.     In this Discovery program, we will explore an innovative multi-process approach to overcome the limits associated with existing manufacturing methods for ultralight high-strength magnesium (Mg) alloys. Specifically, an advanced powder metallurgy process (Spark Plasma Sintering, SPS) will be combined with a traditional metalcasting process to develop novel Mg alloy composites containing graphene-based additives. A critical goal will be to develop composites suitable for mass production, yet remaining cost efficient. Using SPS, graphene-based additives (e.g., graphene, graphene oxide or reduced graphene oxide) will be combined with Mg powder and sintered to form a master alloy. The sintered master alloy will be then subsequently added to liquid Mg alloys during casting operations, resulting in the dissolution of the Mg master alloy within the melt, followed by the release of the graphene-based additives in the melt. The additives will serve to simultaneously enhance the strength and ductility (via grain refinement and the modification of eutectics) and thermo-electric properties of the alloys. Using this approach, several critical challenges (e.g., particle settling, flotation or oxidation) associated with current treatment methods for liquid Mg alloys will be surpassed. Further, the novel composite alloys will be particularly tailored towards applications in the next-generation of hybrid / electric vehicles.     In addition to developing novel alloys for mass-produced Mg parts, our group will also investigate the effect of SPS process parameters and powder morphology on the sinterability of the master alloys and their interaction with the graphene-based additives. The generated knowledge will enable sintering of materials with precisely controlled microstructure and properties.     Experimental work in both areas will be carried out at my UBC laboratories and will provide HQP hands-on and fundamental knowledge in the fields of manufacturing and materials science. This program will provide a foundation for a novel approach to develop castable high-strength Mg alloys.