A new heat treatment process known as Up-Quenching makes an aluminium alloy for automotive construction both strong and easy to shape.
Researchers at the University of Leoben have developed Up-Quenching, a novel heat treatment concept, that enables better formability of conventional aluminum alloys for automotive construction while maintaining high strength.
In order to reduce greenhouse gas emissions, automotive manufacturers are increasingly turning to aluminium, which is three times lighter than conventional steel. However, especially in the area of car body outer panels (engine hoods, door panels, trunk lids), complex designs are leading to increasing demands in terms of formability, which requires the optimization of existing aluminium alloys.
Improved properties through Up-quenching
Following the conventional manufacturing route for aluminium alloys, an increase in strength is mostly associated with a decrease in formability. A team of researchers led by Prof. Dr. Stefan Pogatscher from the Chair of Nonferrous Metallurgy at the Montanuniversitaet Leoben has successfully tackled this problem.
By the means of simulations, a completely new type of heat treatment was found, which relies on rapid heating - up-quenching - instead of the usual rapid quenching.
New heat treatment for car manufacturing
In this context, Dr. Florian Schmid, PostDoc in the Christian Doppler Laboratory for Advanced Aluminium Alloys, explains: "Typically, aluminium alloys are heated only once in a classical heat treatment, which is followed by immediate quenching. Repeated short-term heating to an intermediate temperature can produce properties within a few hours that otherwise can only be realized over an uneconomically long period of more than a week." The new process accelerates the formation of nanometer-sized atomic clusters, which provide a unique path to high strength while maintaining good formability. In a groundbreaking article in the new Nature Research journal "Communications Materials," the researchers demonstrate the principle and capabilities of this novel process route. Based on this, the use of aluminium in the transportation sector should become even more attractive.