In the component repair process using additive manufacturing (AM) technique, reconstructing the repair volume is essential to generate the repair tool path and guide the AM system to deposit correct geometry on the worn parts. In this study, a novel repair volume reconstruction methodology based on voxel modeling was introduced. At first, the stereolithography (STL) models of the nominal and damaged components were acquired either from computer-aided design (CAD) modeling or through robot-aided 3D scanning. The pre-machining approach was introduced to guarantee the defective zone is accessible to repair tools. The damaged models were aligned with the nominal models by best-fitting their common convex-hull centroids. After that, these STL models were converted to voxel models using the Marching Cube algorithm. The accuracy of the transferred voxel models was investigated by comparing them with the exact geometry. Boolean operations algorithm based on constructive solid geometry was proposed to extract the repair volume by comparing the nominal and damaged voxel models. The Boolean operations can output both the repair volume that is missing from the damaged parts which should be restored by AM and the excess geometry which should be removed by subtractive machining. The proposed approach was implemented on three CAD models and three scanned models. The repair volumes for these damaged parts were successfully reconstructed. Three components were repaired via the directed energy deposition AM process. Finally, the bonding performance between the deposited layers and base parts was evaluated via tensile testing.

在使用增材制造（AM）技术的零件修复过程中，重建修复体积对于生成修复工具路径并引导AM系统在磨损的零件上沉积正确的几何形状至关重要。在这项研究中，介绍了一种新的基于体素建模的修复体重建方法。首先，通过计算机辅助设计（CAD）建模或通过机器人辅助3D扫描获取标称和损坏组件的立体光刻（STL）模型。引入了预加工方法，以确保修复工具可以访问缺陷区域。通过最适合其常见的凸包质心，将损坏的模型与名义模型对齐。之后，使用Marching Cube算法将这些STL模型转换为体素模型。通过将其与精确的几何图形进行比较，研究了转移的体素模型的准确性。提出了一种基于构造实体几何的布尔运算算法，通过比较名义和受损体素模型来提取修复量。布尔运算可以输出应通过AM恢复的损坏零件中缺少的维修量，以及应通过减法加工去除的多余几何体。所提出的方法在三个CAD模型和三个扫描模型上实现。这些受损零件的维修量已成功重建。通过定向能量沉积AM工艺修复了三个组件。最后，通过拉伸测试评估了沉积层与基础部件之间的粘合性能。