The Norwegian project “Modeling-assisted Innovation for the aluminum DC Casting Process” (MINAC), has developed modeling tools that show the impact of even minute adjustments to the casting process on casthouse products. The research being carried out in the MINAC project is of interest both for the quality-focused automotive industry, which is striving to develop cars that are lighter and more environment-friendly, and for the construction industry, where the products used must also satisfy stringent requirements.
The aluminum industry is facing three major challenges: increasingly complex products; demanding customers; and ever more stringent recirculation and recycling requirements. This means that the industry is in need of a predictable and reliable casting process that is not based on trial and error.
|New, user-friendly modeling tools put the aluminum industry in a position to simulate the outcomes of choosing certain alloys and casting parameters, thereby increasing processability. (Illustration: SINTEF) Click to enlarge.|
Aluminum is one of Norway’s largest export products. The automotive and construction industries are both large consumers of Norwegian aluminum. Most of the aluminum exported is primary aluminum, an alloy produced via an electrolytic reduction process. But the industry is changing and the emerging trend is to use more recycled materials in cars as well as in construction.
Producing aluminum the first time around is a relatively expensive and energy-intensive process. After the initial production, however, aluminum can be re-melted and recycled countless times. The recycling process we are working on is far less costly than the initial production process, largely because the total amount of energy needed for recycling is only five per cent of what was used originally. These savings, combined with more environmentally sustainable processes, make it far more attractive to use recycled aluminum.—Hydro aluminum’s Ole Runar Myhr, project manager of the MINAC project
The aluminum casting process entails multiple challenges, caused among other things by impurities and variations in chemical composition in the material to be cast. Both factors can compromise the final product through the formation of cracks, uneven surface quality and more.
For example, if intrusions or overly large particles arise during the casting process, the resulting sheet ingots that are later rolled into aluminum foil may contain weaknesses and tear easily, and the final product may prove defective.
Launched in 2009, the MINAC project builds on researcher-driven expertise from as far back as the early 1970s. The objective has been to create and further refine modeling tools that the aluminum industry can use to simulate the outcomes of choosing certain alloys and casting parameters, thereby increasing processability. Greater predictability in the casting process reduces the occurrence of casting defects which otherwise result in large additional costs. Another increasingly important area of application for the simulation tools developed under the MINAC project include the certification of new alloys for high-demand customers in the transport and construction sectors.
Industrial partners in the project include Hydro aluminum, Alcoa and Aleris. These three actors, competitors in several areas, have come together to form a forward-looking consortium that will continue even after the MINAC project’s lifetime.
Other key partners include the Research Council of Norway’s Programme for User-driven Research-based Innovation (BIA), SINTEF Materials and Chemistry and the Institute for Energy Technology (IFE). The BIA programme has provided vital funding to the project while the specialist knowledge of IFE and SINTEF Materials and Chemistry in the development of advanced models has been pivotal in making the project so successful.
The MINAC project was concluded in the summer of 2013, having achieved most of what we had set out to do. It is particularly satisfying to see one of the most important objectives fulfilled—developing an entirely new model capable of solving the problem of variations in the chemical composition through the cast product.—Dr. Myhr
In addition, we have further developed modules designed to help to reduce the risk of casting defects during production and to tailor microstructure formation during casting and the heat treatment that follows. All new modules have been adopted and implemented by the industrial partners after the development and testing carried out during the project.—Dr. Kjerstin Ellingsen, Senior Research Scientist at SINTEF Materials and Chemistry