工程师在东京科学大学（TUS）已经开发了一个数学模型，能够预测有向能量沉积（DED）生产的零件的性能，然后再打印3D。
Using their approach, the team has found it possible to identify how the DED process will perform, in terms of temperature distribution, deformation state, and residual stress distribution, in advance. With further tweaking, the researchers say their model could be deployed to make the technology more efficient, particularly within repair applications.
TUS Masayuki Arai教授解释说：“使用我们的技术，可以在现场恢复金属结构的表面形状，并且可以大大降低维修所需的金属粉末。”“但是，该技术在行业中广泛应用所需的最佳形成条件必须由试验过程确定。”
DED：工业维修解决方案？
正如您所期望的那样，当工业机械中使用的机械零件开始变薄或开发裂缝时，需要将它们替换为新的。但是，尽管3D打印已经显示出可能作为进行这些维修的一种手段，但TUS的研究人员说，许多当前的激光或电子束基3D打印技术“需要使用笨重的设备和废金属粉末。”
也就是说，随着工业可持续性越来越成为一个热门话题，大量的研发正在识别该问题的新解决方案。作为工业和航空航天维修工具，一项继续吸引人的技术是DED的。通常，该过程涉及将粉末或线原料的沉积在表面上，该表面是由聚焦能源沉积的。
鉴于沉积这些材料的喷嘴没有固定在特定轴上，因此可以将其安装在多轴机器上并以各种角度部署。这不仅使该技术理想地将材料存放到维修应用中的现有表面上，而且根据TUS团队的说法，它可以通过大量降低的足迹来实现。
然而，尽管作为一种工业维修工具而获得了吸引力，但它尚未在该领域获得广泛的采用。As identified by the TUS team, this is somewhat down to how difficult it is to find the optimal parameters for producing a part that’ll meet end-use requirements, and some early adopters have therefore been forced into a ‘trial and error’ approach.
Taking a numerical simulation approach
In an effort to make DED 3D printing outcomes more predictable, the TUS engineers have come up with a numerical processing analysis system for automatically determining a build’s optimal forming conditions. The software does so via something called a ‘death-birth algorithm,’ which works by numerically simulating the restoration process, and creating a ‘digital twin’ of the area being repaired.
“将热辐射热传导模型和粘塑性 - 心形塑性组成型模型应用于构成沉积区域的堆叠元素，因此可以忠实地模拟从融化到沉积金属粉末的固化层的广泛变化，”阿莱教授补充说。“通过将这些模型纳入有限元分析程序中，我们开发了一种从未使用过的新加工分析系统。”
After deploying their model in testing, the team found that its temperature history and strain behavior estimates were in “good agreement with their experimental results.” It was also confirmed that the residual stresses formed in deposited layers were slightly above the yield strength of the base material, and significantly lower than those formed during weld overlaying, another industrial repair process.
利用他们的模型，研究人员认为，最终有可能使DED更有效的维修技术“具有有效的资源管理来提高其可持续性”。在应用方面，他们看到其软件被部署以修复发电厂叶片上的气蚀变薄，以及受残余变形影响的燃气轮机转子叶片。
Though not yet applied at scale in energy and aerospace, DED continues to gain traction as means of repairing turbine blades in these industries. In late 2021, it was revealed that a long-standing client had begun usingOptomec 3D打印用于涡轮刀片维修。该公司以前还获得了500,000美元的授予，以部署其镜头DED技术美国空军涡轮刀片维修。
Elsewhere, in a similar project to that of the TUS team, a German-Canadian consortium has set out toautomate repair 3D printing using AI。作为“ AI-SLAM”计划的一部分，该团队正在开发算法的软件，该软件可以管理DED过程，以更有效地修复受损部件的不规则表面，而无需任何人类输入。
The researchers’ findings are detailed in their paper titled “通过激光直接能量沉积对修复过程的三维数值模拟,” which was co-authored by Masayuki Arai, Toshikazu Muramatsu, Kiyohiro Ito, Taisei Izumi, and Hiroki Yokota.
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特色图显示了Optomec的镜头DED技术进程。通过Optomec的照片。
