Nucleation potency prediction of LaB6 with E2EM model and its influence on microstructure and tensile properties of Al-7Si-0.3Mg alloy
(1. Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, China;
2. Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Institute of Technology, Nanjing 211167, China)
2. Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Institute of Technology, Nanjing 211167, China)
Abstract: The edge-to-edge matching (E2EM) crystallographic model was used to predict the orientation relationships (ORs) between LaB6 and Al. Three different possible ORs can be predicted between LaB6 and Al, which are (100)Al||(100)LaB6, [001]Al||[001]LaB6; (110)Al||(110)LaB6, [001]Al||[001]LaB6; and (111)Al||(111)LaB6, Al || LaB6. The prediction results are perfectly confirmed through TEM analysis and prove the nucleation potency of LaB6. The refining efficacy of Al-2La-1B refiner and its influence on the tensile properties were investigated in the as-cast Al-7Si-0.3Mg alloy. According to the results, LaB6 has higher nucleation potency than TiB2, leading to better grain refining efficacy of Al-2La-1B refiner in the as-cast Al-7Si-0.3Mg alloy. Regarding the mechanical performances, tensile properties of the as-cast Al-7Si-0.3Mg casting alloy are prominently improved after addition of Al-2La-1B refiner, due to the refined microstructures.
Key words: edge-to-edge matching; orientation relationship; casting aluminum alloy; grain refinement; tensile properties