Snopiński Przemysław, Matus Krzysztof, Hilšer Ondřej, Rusz Stanislav
Department of Engineering Materials and Biomaterials, Silesian University of Technology, 18A Konarskiego Street, 44-100 Gliwice, Poland.
Materials Research Laboratory, Silesian University of Technology, 18A Konarskiego Street, 44-100 Gliwice, Poland.
Materials (Basel). 2023 Jun 9;16(12):4288. doi: 10.3390/ma16124288.
In this work, we used an AlSi10Mg alloy produced by selective laser melting (SLM) to study the effects of build direction and deformation temperature on the grain refinement process. Two different build orientations of 0° and 90° and deformation temperatures of 150 °C and 200 °C were selected to study this effect. Light microscopy, electron backscatter diffraction and transmission electron microscopy were used to investigate the microtexture and microstructural evolution of the laser powder bed fusion (LPBF) billets. Grain boundary maps showed that the proportion of low-angle grain boundaries (LAGBs) dominated in every analysed sample. It was also found that different thermal histories caused by the change in build direction resulted in microstructures with different grain sizes. In addition, EBSD maps revealed heterogeneous microstructures comprising equiaxed fine-grained zones with ≈0.6 μm grain size and coarse-grained zones with ≈10 μm grain size. From the detailed microstructural observations, it was found that the formation of a heterogeneous microstructure is closely related to the increased fraction of melt pool borders. The results presented in this article confirm that the build direction has a significant influence on the microstructure evolution during the ECAP process.
在本研究中，我们使用通过选择性激光熔化（SLM）制备的AlSi10Mg合金，来研究构建方向和变形温度对晶粒细化过程的影响。选择0°和90°两种不同的构建取向以及150°C和200°C的变形温度来研究此效应。利用光学显微镜、电子背散射衍射和透射电子显微镜来研究激光粉末床熔融（LPBF）坯料的微观织构和微观结构演变。晶界图表明，在每个分析样品中低角度晶界（LAGB）的比例占主导。还发现，构建方向变化导致的不同热历史会产生具有不同晶粒尺寸的微观结构。此外，电子背散射衍射图揭示了由尺寸约为0.6μm的等轴细晶粒区和尺寸约为10μm的粗晶粒区组成的不均匀微观结构。通过详细的微观结构观察发现，不均匀微观结构的形成与熔池边界比例的增加密切相关。本文给出的结果证实，构建方向对等通道转角挤压（ECAP）过程中的微观结构演变有显著影响。
