Mechanical Behavior of Differently Oriented Electron Beam Melting Ti-6Al-4V Components Using Digital Image Correlation
Mechanical Behavior of Differently Oriented Electron Beam Melting Ti-6Al-4V Components Using Digital Image Correlation
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DOI：
10.1115/1.4040553
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发表时间：
2019-01-01
影响因子：
1.2
通讯作者：
Wicker, Ryan B.
中科院分区：
文献类型：
--
作者：
Arrieta, Edel;Haque, Mohammad;Wicker, Ryan B.
添加剂制造的金属部件的机械性能会受到层沉积取向的影响。在本研究中，用电子束熔炼(EBM)制备了四种不同角度(0°、30°、60°和90°)的Ti-6Al-4V圆柱形试件，并按照ASTM E8《金属材料拉伸试验标准试验方法》进行了试验。由于逐层制造表明赋予构件各向异性特性，通过数字图像相关(DIC)记录应变场，以寻找单轴载荷下的剪切效应。为了验证这种测量方法的有效性，用夹式引伸仪和虚拟引伸仪同时测量了轴向应变。对不同方位的试件进行了破坏分析，证明了剪切应变场的记录。失效分析包括断口、显微组织分布的光学照片以及显示与分层方向相关的不同失效特征的失效轮廓。此外，还给出了一个实验研究案例，说明如何从制造过程中潜在地设计部件的失效模式。最后，对剪切效应进行了讨论，并对通过失效进行构件设计的可能性进行了探讨。
Mechanical properties of additive manufactured metal components can be affected by the orientation of the layer deposition. In this investigation, Ti-6Al-4V cylindrical specimens were fabricated by electron beam melting (EBM) at four different build angles (0 deg, 30 deg, 60 deg, and 90 deg) and tested as per ASTM E8 Standard Test Methods for Tension Testing of Metallic Materials. With the layer-by-layer fabrication suggesting granting anisotropic properties to the builds, strain fields were recorded by digital image correlation (DIC) in the search for shear effects under uniaxial loads. For the validation of this measuring method, axial strains were measured with a clip extensometer and a virtual extensometer, simultaneously. Failure analysis of the specimens at different orientations was conducted to evidence the recording of shear strain fields. The failure analysis included fractography, optical micrographs of the microstructure distribution, and failure profiles displaying different failure features associated with the layering orientation. Additionally, an experimental study case of how the failure mode of components can potentially be designed from the fabrication process is presented. At the end, remarks about the shear effects found, and an insight of the possibility of designing components by failure for safer structures are discussed.