Research to develop aluminium alloys for lightweight vehicles

CIC marGUNE is coordinating a line of research in the Basque Country for developing aluminium alloys with enhanced properties. Aluminium alloys are the future of the automobile sector. Until recently and due to the high costs involved, they have been used solely in aeronautics and, in the case of cars, in interiors or for accessories, aluminium alloys are replacing steel in order to achieve lighter and less contaminant vehicles.

These materials with enhanced properties are the result of the research work coordinated by CIC marGUNE, the High Performance Cooperative Manufacturing Research Centre, in collaboration with companies and technological centres in the Basque Country. The work undertaken by these bodies is achieving the enhancement of the mechanical properties of aluminium alloys, through micro-additions of certain elements.

Basically there exist two procedures for the manufacture of aluminium alloys and which differ mainly in the raw material used. In one of these, the raw material is bauxite, a mineral rich in aluminium. The most important disadvantage of this procedure is the high quantity of energy needed in order to produce the aluminium and the high generation of waste, as pointed out by IK4-Azterlan researcher, Ana Isabel Fernández-Calvo.

A second technique for obtaining aluminium is through recycling of the waste metal and other waste rich in aluminium. The costs are less with this procedure but the main disadvantage is the high content of impurities, especially iron. Iron is the most common impurity, having a negative repercussion on the mechanical properties of aluminium alloys. The elimination or reduction of its content is technically complex and costly. In order to resolve this problem, small quantities of alloying elements such as manganese, chromium, vanadium or beryllium are added. These elements help reverse the prejudicial effect of the iron impurities in the recycled aluminium and even enhance the mechanical properties of the alloy. “In short, the key lies in the modification of the morphology by using these elements”, added Mr Marcos Pérez, researcher at IK4-Azterlan.

Aluminium alloys are currently used in the moulding of safety parts such as components for the automobile and aeronautics industries (car wheel rims, steering knuckles, brake parts, and so on), all requiring high-performance mechanical properties. These new alloys enhance such properties.