Additive Manufacturing of AlSi10Mg Alloy Using Direct Energy Deposition: Microstructure and Hardness Characterization
Additive Manufacturing of AlSi10Mg Alloy Using Direct Energy Deposition: Microstructure and Hardness Characterization
复制标题
DOI：
10.1007/s11666-016-0495-4
复制
发表时间：
2017-04-01
影响因子：
3.1
通讯作者：
Brochu, M.
中科院分区：
文献类型：
--
作者：
Javidani, M.;Arreguin-Zavala, J.;Brochu, M.
本文对直接能量沉积(DED)法制备AlSi10 Mg合金进行了研究。制备完成后，利用光学显微镜和扫描电子显微镜初步研究了样品的宏观和微观结构演变。柱状枝晶组织是沉积的主要凝固特征，但详细的显微组织分析表明，在沉积基材附近有胞状组织，在沉积的顶端有等轴状树枝晶。此外，沉积层熔池边界的显微组织形态与层状中心的组织形态不同。用阿基米德原理和抛光表面的图像分析评价了镀层的剩余孔隙率。用电子背散射衍射仪和X射线衍射仪对镀层的晶体织构进行了分析。枝晶是单向取向的，与基片成80度角。EPMA线条扫描用于评估不同位置的成分变化和元素偏析。最后，进行了显微硬度(HV)测试，以研究AS-DED处理样品中沿沉积方向的硬度梯度。研究结果表明，采用DED法制备的Al-Si基合金具有较好的致密性，其沉积组织几乎无缺陷。
This paper aims to study the manufacturing of the AlSi10Mg alloy with direct energy deposition (DED) process. Following fabrication, the macro- and microstructural evolution of the as-processed specimens was initially investigated using optical microscopy and scanning electron microscopy. Columnar dendritic structure was the dominant solidification feature of the deposit; nevertheless, detailed microstructural analysis revealed cellular morphology near the substrate and equiaxed dendrites at the top end of the deposit. Moreover, the microstructural morphology in the melt pool boundary of the deposit differed from the one in the core of the layers. The remaining porosity of the deposit was evaluated by Archimedes' principle and by image analysis of the polished surface. Crystallographic texture in the deposit was also assessed using electron backscatter diffraction and x-ray diffraction analysis. The dendrites were unidirectionally oriented at an angle of similar to 80 degrees to the substrate. EPMA line scans were performed to evaluate the compositional variation and elemental segregation in different locations. Eventually, microhardness (HV) tests were conducted in order to study the hardness gradient in the as-DED-processed specimen along the deposition direction. The presented results, which exhibited a deposit with an almost defect free structure, indicate that the DED process can suitable for the deposition of Al-Si-based alloys with a highly consolidated structure.