High temperature high strength Al alloy development for additive manufacturing

Selective laser melting (SLM) of metallic components are now offering a new avenue for high-end components making due to its inherent unlimited design freedom, high material utilisation and short production lead time. However, the SLM process currently still faces fundamental issues of material processability (mainly solidification cracks) and limited mechanical properties. This is because most of the current applied alloys are originally designed for traditional processing and few of them are developed to take advantage of the benefits offered by the SLM process. In this study, we have successfully developed a high temperature high strength aluminium alloy specifically for SLM. The highly enhanced alloy room temperature properties (with yield strength up to 570 MPa), good processability (no solidification cracks) and simple post heat treatment (only requires direct ageing) of the developed alloy offers tremendous benefits for the fabrication of complex high performance lightweight engineering components made by SLM. The developed alloy also demonstrates excellent thermal stability and superior high temperature properties, which provides the potential to replace some Fe and Ti parts serviced at medium temperatures (200-300 °C)