“The aluminium content in aluminium vehicle body structures has been growing steadily for over 20 years and continues to accelerate across the automotive market” stated Mr. Adrian Tautscher, Presenter and Chairman at the Vehicle Recycling International Conference 2018 held in Munich in October. His view on the benefits of using aluminium are clear, “When aluminium is applied to optimise an automotive body structure, a weight saving of around 40% is achievable when compared to a steel based structure. These weight savings in the structure then allow other vehicle systems to be downsized such as the engine and gearbox, and in the case of electric vehicles it enables a smaller battery and/or improved range.” He added, “Weight reduction for car makers will continue to be a significant theme and this increasingly means that the End-of-Life infrastructure will need to adapt and keep pace with this opportunity as the earlier generations of cars with higher aluminium content reach End-of-Life and enter the automotive recycling value chain”.
The theme of the conference was very much on the challenges and complexities of End-of-Life, including the materials challenges, case studies, legislative demands and the challenges of battery electric vehicles. Just taking aluminium on its own, Mr. Tautscher explained that the value equation is a key driver, “Vehicles by mass are mainly metals based, and aluminium as a high value commodity can achieve even higher value through separation between the alloy types. Recyclers have the opportunity to further improve materials separation”. A further point he made related to the growing aluminium capital embedded in the current automotive stock that is starting to feed through. “A typical vehicle life is around 15 years in the UK so most of the aluminium intensive cars are still in use but eventually they will enter the recycling supply chain which becomes a very positive opportunity for the recyclers to liberate as fully as possible the value of aluminium and improve the overall recycling approach to keep material quality as high as possible”. When asked about how this can be achieved, Mr. Tautscher expanded on this aspect, “Typically when cars are shredded, the aluminium is contained in the light alloy fractions sometimes referred to as Zorba. A key development will be to use the latest sensor based sorting systems to separate the shredded outputs, ideally this means splitting the cast aluminium alloys from the sheet/wrought alloys, and then separation within each alloy group. As an example, one approach could be to separate high and low silicon casting alloys and separate the sheet aluminium between high and low copper aluminium alloys. The key challenge is to get the overall system to work economically, to overcome the initial investment and run at the required high speed of the shredding lines”.
Mr. Tautscher’s view is that this is not the end of the story. A further enabler is to make use of complementary technologies to absorb the shredded and separated aluminium from End-of-Life to go back into high quality automotive components. Part of his role at Impression Technologies is to investigate the potential of the hot formed aluminium HFQ® Technology process to make greater use of recycled aluminium. Mr. Tautscher went on to say that “HFQ® is a novel method of pressing rolled aluminium sheet that enables greater tolerance to the altered chemistry that will result from increased recycled aluminium content, and still allow intricate and deeper drawn part geometries to be created without splitting or degradation. Conventional cold forming of aluminium reaches its limit much sooner especially with increases in iron and silicon within the aluminium chemistry which usually results even from higher quality segregated recycled aluminium”.
Mr. Tautscher identified that the critical path will be the sector working together “This does require a joined up approach; the aluminium sheet/alloy producers working with the recyclers as they improve separation, along with processes like HFQ® as a secondary enabling technology to absorb the scrap. The benefit will be high quality/high performance parts creating demand for recycled aluminium from secondary sources delivering CO2 reductions, along with increased revenue on scrap to help achieve a small but credible step to creating an integrated automotive recycling value chain”.
To find out more about the processes mentioned in this article, you can contact:
Adrian Tautscher Principal Technical Specialist
Impression Technologies Ltd