Heat treatment behaviour of aluminium alloy Al-7Si-0.6Mg produced by laser additive manufacturingWednesday (08.11.2017) 12:00 - 12:20 Part of:
Laser additive manufacturing (LAM) is a 3D-printing technology for metals with great attraction for aerospace and automotive industries, especially when it is applied to high strength aluminium alloys. The main characteristics of LAM are freedom of design, fabrication in just one step and high cooling rates during the manufacturing process. The latter leads to a microstructure which differs from conventionally cast components.
The present report aims to characterize the heat treatment behaviour of aluminium casting alloy A357 (Al-7Si-0.6Mg) made by selective laser melting in comparison with conventional manufacturing by permanent mould casting. Therefore, some laser fabricated samples have been remelted to get cast specimens. For each kind of sample, electrical conductivity and hardness have been measured after solution treatment at 540 °C for various durations from 5 to 240 minutes and artificial ageing at 160 °C. Tensile tests, DSC experiments and metallographic analysis have been performed.
The results show heat treatment optimization potential for LAM aluminium components, e.g. short solution treatments, which can be explained by the fine microstructure observed in LAM samples. Another beneficial effect of LAM is the highly super-saturated solid solution, offering the possibility to age the alloy directly from the as-built condition.