Kim Kibeom, Ji Yebin, Kim Kwonhoo
Department of Marine Design Convergence Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 48513, Korea.
Department of Metallurgical Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan 48513, Korea.
Materials (Basel). 2022 Aug 4;15(15):5367. doi: 10.3390/ma15155367.
To enhance the formability of magnesium alloys, inhibition of basal texture development by the particle-stimulated nucleation (PSN) effect has attracted significant interest. However, its contribution to texture development is not easily observed due to the separation of texture from the conventional deformation behavior. This study aims to separate the Ca texture from the deformation behavior of AZX611 alloy and quantify it using scanning electron microscopy with electron backscatter diffraction (SEM-EBSD). Since Ca in the AZ61 magnesium alloy precipitated as AlCa, the hot-rolled magnesium alloys AZ31, AZ61, and AZX611 were used. High temperature compression was conducted at 723 K, the strain rate 0.05/s and 0.005/s and the true strain up to -1.0. Dynamic recrystallization was observed in each specimen and the Ca-free alloys showed dislocation glide at high strain rates and solute drag at low strain rates. When the dislocation glide dominated, basal texture was strengthened. In contrast, solute drag caused non-basal texture development. Precipitation hardening caused AZ61 to have higher flow stress than those of the Ca-free alloys by the PSN effect; its texture was observed separately because the PSN grain growth around the precipitation and orientation was specific, similar to the one developed at the solute atom drag.
为提高镁合金的可成形性,通过粒子激发形核(PSN)效应抑制基面织构的发展引起了广泛关注。然而,由于织构与传统变形行为的分离,其对织构发展的贡献不易观察到。本研究旨在从AZX611合金的变形行为中分离出Ca织构,并使用带有电子背散射衍射的扫描电子显微镜(SEM-EBSD)对其进行量化。由于AZ61镁合金中的Ca以AlCa形式析出,因此使用了热轧镁合金AZ31、AZ61和AZX611。在723 K下进行高温压缩,应变速率为0.05/s和0.005/s,真应变高达-1.0。在每个试样中均观察到动态再结晶,无Ca合金在高应变速率下表现出位错滑移,在低应变速率下表现出溶质拖拽。当位错滑移占主导时,基面织构得到强化。相反,溶质拖拽导致非基面织构的发展。析出硬化使AZ61由于PSN效应而具有比无Ca合金更高的流动应力;由于析出物周围的PSN晶粒生长和取向具有特异性,类似于溶质原子拖拽时形成的织构,因此其织构得以单独观察。