Effects of TiB2 additions on microstructure and mechnical properties of Al–Mg–Sc alloy fabricated by selective laser melting
Min Wu, Jing Tao, Jihao Wang, Wei Jiang, Yueming Sun, Dingping Dong, Yu Zhao, Mengmeng Wang, Tong Liu, Liangshun Luo, Yanqing Su
Abstract
In this paper, the effect of TB2 additions on a noval Al–Mg–Sc alloy was studied, and the microstructure and mechanical properties of SLM-fabricated TiB2/Al–Mg–Sc alloys were investigated. The results showed that molten pool width increased and molten pool depth slightly decreased with TiB2 increase, due to the laser absorptivity of the TiB2/Al–Mg–Sc alloys higher than that of Al–Mg–Sc alloy under the same process parameters. The microstructure of SLM-fabricated TiB2Al–Mg–Sc alloys were composed of fine-grained, coarse-grained and columnar-grained regions, and the fine-grained region increased with the increase of TiB2 content. The recrystallization regions in SLM-fabricated TiB2/Al–Mg–Sc alloy decreased with the increase of TiB2 content, and TiB2 additions used as heterogeneous nucleation to refine grains, which can pin grain boundaries and prevent recrystallization during SLM process. TiB2/Al–Mg–Sc alloy with 1% TiB2 additions showed a relatively higher comprehensive mechanical properties, and the tensile strength is 483 MPa, the elongation is 15.8%. Tensile strength of 1%TiB2/Al–Mg–Sc alloy was increased by 37 MPa and the elongation is also increased by 2.1% compared with 0%TiB2/Al–Mg–Sc alloy, and 2%TiB2/Al–Mg–Sc alloy shown a relatively lower comprehensive mechanical properties due to its lower density and TB2 agglomerated.