Healable aluminium-magnesium alloy processed by laser powder bed fusion

The main goal of this thesis is to design, produce and characterize a healable aluminum-magnesium alloy manufactured by laser powder bed fusion. With Scheil modelling the composition is set to be Al-Mg14. The healing behavior with the eutectic phase melting will be examined. The manufacturing process was optimized with the given composition and relative density above 99% was reached. Magnesium evaporation is observed as the Mg content dropped from 13.6 wt% to 8.2 wt% after manufacturing. The manufactured samples have a fine dendritic structure and their hardness value is at around 110 HV. Tensile samples under as-built condition have a low ductility due to the presence of hot cracks. Lastly, heat treatment at various temperature was applied to samples. A moderate increase in ductility was seen in the heat-treated tensile samples. Porosity reduction and crack healing were observed with tomography. The degree of healing is around an 8.3% reduction of the existing porosity and 2-3 micrometre of crack width reduction.