Investigating the Effect of Direct Aging and Stress Relieving Treatment on Microstructure and Mechanical Properties of AlSi10Mg Fabricated through LPBF

The ability of additive manufacturing (AM) technology in producing near-net shaped and functional grade metallic parts has led to its wide acceptance and usage in several mainstream sectors like aerospace, automotive, biomedical etc. Additionally, the evolution of cost-efficient production machines helped in rapid adoption of the AM technologies for commercial production. Aluminium and its alloys have high strength-to weight ratio, reasonable mechanical properties, good corrosion resistance and high conductivity and hence are widely used in automobile and aerospace industries. AlSi10Mg is one of the popular commercial AM alloy and it was tested for several aerospace applications like aircraft oil cooler, star tracker camera bracket, etc. Since, AM imparts unique microstructural characteristics to AlSi10Mg and conventional T6 heat treatment destroys these characteristics, several new heat treatments have been proposed for AlSi10Mg manufactured through AM. However, there is a temperature gap between direct ageing and stress relieving treatments, which are not very well investigated. This work investigates the effect of direct ageing (DA) at 245 °C on microstructure and mechanical properties in AlSi10Mg fabricated using laser bed fusion (LPBF) technology. The properties of DA samples are analysed and compared with as-built and stress-relieving treatment (T5).