Title : Status and Prospect of Al alloys for Additive Manufacturing
Additive Manufacturing technology is being adopted in more and more industries and the focus of research and development is shifting to the materials in use. However, limited processability of high-performance Al alloys restrict the robustness of the process in some cases, while in other cases the best Al alloys for a given application cannot be processed at all. Currently only a few alloys can be reliably processed by this methodology, and in particular the number of different aluminium alloys available for AM is still rather limited. The main reason is that the strongest Al alloys, which get their strength from precipitation hardening, contain highly volatile elements such as Zn, Mg, etc. leading to turbulent pools, pores and low mechanical properties. In the first part, this talk will review the current state of the art of the Al alloys for AM. In the second part, the latest research on development of the innovative aluminium alloy specifically designed for SLM will be described. Two different approaches will be presented: on one hand, on tailoring the chemical composition to improve processability, specifically crack susceptibility of wrought aluminium alloys of the 7xxx series (Al-Zn alloys) and on the other, to increase mechanical resistance of weldable casting grade AlSi10Mg alloy. A special emphasis will be placed on powder production by gas atomization as a first and an important step in alloy development for additive manufacturing. It will be shown how the desirable compositions can be achieved and what are the main challenges faced. Also the properties of the powders will be assessed and processability by SLM demonstrated. Finally, the properties of the new alloys will be presented and compared with the traditional ones.
State-of-the art of Al alloys for Additive manufacturing. Main challenges and approaches to meet them. Latest research on development of the innovative aluminium alloy specifically designed for SLM. New Al alloys that can be 3D printed with the same or even better properties than the Al7075 alloy which is considered the best Al alloy for structural applications.