Determination of Anisotropic Mechanical Properties for Materials Processed by Laser Powder Bed Fusion
Determination of Anisotropic Mechanical Properties for Materials Processed by Laser Powder Bed Fusion
复制标题
DOI：
10.1155/2018/7650303
复制
发表时间：
2018-01-01
影响因子：
--
通讯作者：
Andreassen, Erik
中科院分区：
文献类型：
--
作者：
Hovig, Even W.;Azar, Amin S.;Andreassen, Erik
提高增材制造的成功率和设计高度优化的结构需要正确理解材料行为。这项研究提出了一种新的实验方法，通过该方法可以评估增材制造材料的各向异性力学性能。该程序基于对通过激光粉末床熔合（LPBF）在相对于构造板的不同方向上制造的扁平样本进行拉伸试验。在这项研究中，该程序被应用到Inconel 718合金。构建了三个相同的样本集，每个样本集都接受了互补的后处理。拉伸试验是在具有竣工表面光洁度的试样上进行的。利用数字图像相关技术记录了拉伸试样在加载过程中两垂直表面上的应变场演化。本文还提出了一种仅用少量拉伸试验结果确定各向异性弹性常数的优化算法。据观察，构建方向和后处理对材料的各向异性机械性能有很大的影响。微观结构的影响也进行了研究和表征。因此，构造了三个横观各向同性柔度矩阵，代表了不同加工条件的影响。
Improving the success rate in additive manufacturing and designing highly optimized structures require proper understanding of material behaviour. This study proposes a novel experimental method by which anisotropic mechanical properties of additively manufactured materials can be assessed. The procedure is based on tensile testing of flat specimens, manufactured by laser powder bed fusion (LPBF) at different orientations relative to the build plate. In this study, the procedure was applied to the Inconel 718 alloy. Three identical specimen sets were built, each of which received complementary postprocessing treatments. The tensile tests were carried out on specimens with as-built surface finish. Digital image correlation was used to record the strain field evolution on two perpendicular surfaces of the tensile specimens under loading. An optimization algorithm is also proposed for determining the anisotropic elastic constants using only a few tensile test results. It was observed that both build orientation and postprocessing have strong influence on the anisotropic mechanical properties of the material. The effect of microstructure was also investigated and characterised. Consequently, three transversely isotropic compliance matrices were constructed, representing the effect of the different processing conditions.