Evaluation of inter-phase strains present in as-built and heat treated LPBF AlSi10Mg materials

Laser Powder Bed Fused (LPBF) AlSi10Mg materials exhibit increased as-built yield strength when compared to conventional as-built cast products due to the fine silicon network and small grain size resulting from the very fast cooling rates occurring after the laser-induced melting. However, these fast cooling rates lead to the generation of both long-range residual stresses and short range intergranular and interphase stresses, the latter between the Al-alpha matrix and the Si eutectic phase. To this date, the role of the Al/Si interphase stresses and strains is not well elucidated. In order to improve our understanding of the potential role of these short-range stresses on fatigue crack propagation, it is necessary to characterise their magnitude relative to the long-range stresses. This proposal intends to examine the interphase strains present in as-built and heat treated LPBF AlSi10Mg between the Al-alpha matrix and the Si phase.