Abstract
Part 1: AlSi10Mg components produced by laser powder bed fusion (LPBF) typically exhibit higher strength but lower ductility than those made by conventional mature processing technologies. The effects of melt pool boundaries on the ductility and fracture behavior of the LPBF-produced AlSi10Mg have not been systematically studied. The focus of this work is to investigate the local strain evolution, microvoid growth, and crack formation in the melt pool boundary regions using in situ tensile testing and synchrotron-based X-ray microtomography. we offer a new opportunity to fabricate AlSi10Mg products with an excellent combination of high strength and ductility.
Part 2: Laser-based directed energy deposition (LDED) enables rapid near-net-shape fabrication of large-scale titanium components for aerospace applications. However, the poor tensile ductility of most as-deposited titanium alloys, particularly near-α alloys, hinders their wide usage for critical load-bearing structures. Here we report that a high density of microscale shear bands (MSBs) can be activated in an LDED-produced Ti-6Al-2Zr-1Mo-1V alloy with dispersed microscale α colonies to enhance its tensile ductility. U Our study demonstrates that activating the MSBs provides a new opportunity to effectively enhance the ductility of LDED-produced titanium alloys and expedite the adoption of this additive manufacturing technology for critical structural applications.