Scalmalloy® = A Unique High Strength AlMgSc Type Material Concept Processed by Innovative Technologies for Aerospace Applications

Unconventional structures in materials may be generated by the corresponding choice of alloys in combination with a rapid extraction of heat. Improved melt spinning procedures allow to solute more than 1.0 wt% Sc in the Al-lattice. Therefore a critical cooling rate is necessary, which can only be achieved by ribbon thickness lower than 25 µm. In the next step, the flakes are usually compressed with high pressures and temperatures, whereby the fine microstructures may be damaged due to grain growth. However, that grain growth can be successfully suppressed by nano-scaled Al3(Sc1-x; Zrx) precipitations. Spark Plasma Sintering (SPS) is a short time sintering technique related to hot pressing, which uses a pulsed electrical current for the direct heating of the sinter body. The use of high heating rates and short dwell times can minimise grain growth, which often leads to improved material properties. Important technological benefits, such as the energy efficiency due to short processing time, fewer processing steps, elimination of the need for sintering aids, and near net shape capability, are possible.