Residual stress effects during additive manufacturing of reinforced thin nickel-chromium plates
Residual stress effects during additive manufacturing of reinforced thin nickel-chromium plates
复制标题
增材制造增强镍铬薄板过程中的残余应力效应
DOI：
10.1007/s00170-022-10256-6
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Patterson E
中科院分区：
文献类型：
--
作者：
Patterson E
相加制造(AM)是一种强大的技术，可以相对快速、廉价和直接地从数字表示中制造具有复杂几何形状的金属部件；然而，在制造过程中产生的残余应力会导致部件变形和机械性能降低，特别是在缺乏旋转对称性和/或具有大长宽比的横截面的部件中。利用激光-粉末床熔融技术在镍铬合金中制作了几何增强薄板，并用立体数字图像相关法测量了其从AM机床基板释放前后的形状。结果表明，残余应力可能会引起严重的离面变形，这种变形可以通过采用封闭式支撑结构或在薄板的加固边缘使用支撑件来缓解，前者大大增加了建造时间，另一方面难以去除和浪费材料。扶壁建造和拆除速度很快，最大限度地减少了浪费，但需要仔细设计。横向的板材需要面外支撑，而纵向的板材既需要面内支撑，也需要面外支撑。在这两种情况下，从底板释放时，平面外变形增加，但通过增量释放导致平面外变形小于平面内尺寸的5%，这一点得到缓解。
Additive manufacturing (AM) is a powerful technique for producing metallic components with complex geometry relatively quickly, cheaply and directly from digital representations; however, residual stresses induced during manufacturing can result in distortions of components and reductions in mechanical performance, especially in parts that lack rotational symmetry and, or have cross sections with large aspect ratios. Geometrically reinforced thin plates have been built in nickel–chromium alloy using laser-powder bed fusion (L-PBF) and their shapes measured using stereoscopic digital image correlation before and after release from the base-plate of the AM machine. The results show that residual stresses cause potentially severe out-of-plane deformation that can be alleviated using either an enveloping support structure, which increased the build time substantially, was difficult to remove and wasted material, or using buttress supports to the reinforced edges of the thin plate. The buttresses were quick to build and remove, minimised waste but needed careful design. Plates built in a landscape orientation required out-of-plane buttresses while those built in a portrait orientation required both in-plane and out-of-plane buttresses. In both cases, out-of-plane deformation increased on release from the baseplate but this was mitigated by incremental release which resulted in out-of-plane deformations of less than 5% of the in-plane dimensions.