Novel Si/Cu-modified Al-Mg alloy achieves crack-free, high-strength parts through PBF-LB
February 12, 2025
Researchers from Central South University, Hunan, China; Nanjing University of Aeronautics and Astronautics, Nanjing, China; and Brunel University London, United Kingdom, have published a paper titled ‘A novel Si/Cu-modified Al-Mg alloy processed by laser powder bed fusion: Crack inhibition, microstructures and mechanical properties.’
The paper covers the use of cost-effective silicon and copper to modify an Al-5.5Mg alloy for Laser Beam Powder Bed Fusion (PBF-LB). This is reported to have achieved a synergetic combination of crack-free features and high strength. It was found that the hot cracking was effectively eliminated in the PBF-LB samples due to the reduction in brittleness temperature range and the formation of fine Al-Mg2Si eutectics.
The strength improvement in the PBF-LB Al-5.5Mg-2Si-Cu alloy (an ultimate tensile strength of 560 MPa, yield strength of 453 MPa and elongation of 9.1%) resulted from a hierarchical structure featured by the refined ɑ-Al grains, sub-micron cellular structures decorated with Mg2Si, S-Al2CuMg nanoparticles and substantial dislocation networks.
The synergistic effects of crack elimination and precipitation strengthening induced via the incorporation of Si/Cu provide a guideline for fabricating crack-free Al-Mg alloys with high strength.
To read the full paper, click here.
