Selective laser melted AlSi10Mg alloy under melting mode transition: Microstructure evolution, nanomechanical behaviors and tensile properties

The effect of the volumetric energy density (VED) on keyhole formation, microstructural evolution and associated mechanical properties AlSi10Mg fabricated by selective laser melting (SLM) has been systematically investigated. results indicated that three modes could be distinguished during process, corresponding to different VED ranges, i.e. conduction mode (<50 J mm-3), transitional (~50–65 (>65 mm-3). A high not only produced defects hydrogen pores, but also generated two types molten pool, a general shallow pool (GSP) keyhole-induced deep (KDP). GSP was mainly consisted an ?-Al matrix, with ~30 µm grains size, enclosed ~500 nm eutectic Si cellular network. grain size KDP less than 15 µm, it both finer network (~200 nm) nano-scale particles. No preferential crystallographic orientation observed within KDP, while strong texture along<111>orientation exhibited in GSP. These were responsible for SLM parts under modes. related mechanisms formation are comprehensively discussed correlation between microstructure is outlined.