Development and Processing of High Strength Creep-resistant Mg-Sn-Ca Alloys with Minor Additions of Al and Si

Project: Research

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Researcher(s)

Description

In recent years, there is renewed interest in the development of a broader range of wrought magnesium alloys for automobile, aerospace and electronic applications in view of their light weight and damping capacity. Among the several wrought alloys being developed, Mg-Al-Zn alloys (AZ-series) are the most popular ones and AZ31 is the chosen one. However, two main drawbacks are limiting their usage: (a) lower resistance to corrosion, and (b) poor creep strength. Of late, efforts are being made towards developing corrosion and creep-resistant alloys based on Mg-Sn-Ca system, where Sn goes into solid solution with Mg and imparts corrosion resistance while Ca gives creep resistance by forming stable intermetallic particles in the matrix. In comparison with AZ31 alloy, these alloys possess a wider window for successful thermo-mechanical processing and are not prone to flow instabilities. However, in order that the strength levels match or even exceed those of AZ31 alloy, it is necessary to develop newer alloys using Mg-Sn-Ca as a platform and by making further minor alloying additions.In this project, a new series of Mg-Sn-Ca alloys will be developed by adding minor amounts of Al and Si, the former to give solid solution strengthening and the latter to enhance the creep resistance by Mg2Si formation at the grain boundaries to restrict their sliding. However, it is possible that such a strengthening might jeopardize the workability and this issue will have to be addressed fundamentally by modeling the hot working behavior and finding an optimum window of parameters for processing the alloys. Two materials models – kinetic analysis and processing maps – will be chosen for the study and the modeling results will be validated on a laboratory scale by forging a chosen component shape and simulating the process using finite element method to obtain the local variations of the relevant process parameters. This project aims at studying the effect of minor additions of Al and Si to a Mg-Sn-Ca alloy on its strength, corrosion, creep and hot workability behavior with a view to develop an alloy that complies with the requirements for applications in automobile and structural sections and as aerospace components.

Detail(s)

Project number9041351
Grant typeGRF
StatusFinished
Effective start/end date1/01/0920/03/12