Evaluation and development of enabling technologies for lightweight automotive structural cast components with wrought aluminum and high performance magnesium alloys

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The motivation for this project initiative is to reduce the overall weight of the automobile by utilizing more AI and Mg alloys for both the chassis and body structure components; thereby, leading to reduction in the use of fuel and emission of harmful C02 gas to the environment. The introduction of AI and Mg in the chassis and body structure of a car would necessitate far superior mechanical properties and performance of the alloys to surpass the stringent safety requirements for structural automotive components. The available AI and Mg casting alloys do not meet these safety requirements wherein an yield strength in excess of 300 MPa and an elongation of at least 1 0% is mandatory. A critical feature in achieving a light weight multi-material solution for the automotive would be the ability to successfully join these components together with a resistance to corrosion and joint strength deterioration. Casting is the most economically viable manufacturing route for both AI and Mg alloys. Recent advances in AI casting alloys and technology has demonstrated the valid feasibility of enabling near net shaped casting of AI wrought alloys with its far superior mechanical and performance properties to their casting alloy counterparts. This joint project initiative is to develop such processes and technologies to enable prototyping of certain critical structural automotive components. Controlled Diffusion Solidification (CDS), Ablation Casting and Semi Solid Processing using High Pressure Die Casting (HPDC) process would be evaluated critically for three families of AI wrought alloys, namely, the 6xxx and 7xxx series of alloys. The research team at Trento, Italy would be working on developing the 6xxx alloy series and the one in Canada would be working on the 7xxx alloy series. Additionally, evaluating the casting of certain high performance Mg alloys in the ablation casting process would also be carried out in this project along with potential alloy development to re-design existing alloys to better suit the ablation casting process in order to maximize the properties and performance of the cast components. An additional task in this project would be to develop and optimize a new dissimilar metal joining process, in upset protrusion joining, based on a patent pending process to combine cast magnesium components with themselves and with other AI and steel components. This initiative will include developing an optimum protrusion design and optimum heating and forging processes to upset the protrusion and lock the two materials together.