Automation and modeling of a novel laser cladding process to repair and rebuild worn components for extreme applications

制造业中最有前途的领域之一是所谓的“先进制造”，它通常指激光和增材制造工艺提供的新可能性。虽然这项技术在聚合物领域（“3D 打印”）已经很成熟，但将该技术应用于金属会带来挑战，严重影响工业规模制造的可行性。该项目专注于增材制造领域的特定子集，目标是修复在极端应用中磨损的零件。此类应用包括在硬岩采矿和油砂开采、超高速木材切割以及航空航天工业复合材料制造（包括推力矢量喷嘴的热阶段）中经历极度磨损的资源型行业。修复焊缝将磨损零件恢复到原来的形状已被证明是非常有效的，因为它们可以改善原始零件的材料性能，同时减少对环境的影响。该方法使用了两种主要技术，一种涉及层沉积（例如激光熔覆），另一种涉及 3D 结构的构建（例如增材制造）。然而，由于每个零件都是独一无二的，目前进行此类修复的过程需要大量劳动力，因此需要用于 3D 扫描和焊接编程的新工艺，以使该技术在经济上适用于更多行业。该项目将开发扫描、编程和焊接此类零件的新技术和工艺。该项目的复杂性源于需要将零件定位、损坏零件的识别和量化与使用 3D 点云数据信息进行稳健的 3D 重建和比较以及基于材料行为的刀具路径规划相结合。沉积过程中金属的固有特性会导致整个新沉积材料发生材料转变和残余应力，这需要进行彻底的研究，并且需要在刀具路径规划中予以考虑。目标是创建一个具有工业 4.0 功能的自动化系统，控制维修过程参数。

One of the most promising areas in manufacturing is what is called "advanced manufacturing," which commonly refers to the new possibilities offered by lasers and additive manufacturing processes. While this technology is well-established in polymers ("3D printing"), applying this technique to metals brings challenges that significantly affect the feasibility on an industrial scale in manufacturing. This project focuses on a specific subset of the area of additive manufacturing, and targets the repair of parts that have been worn out in extreme applications. Such applications include the resource-based industries that experience extreme abrasion in hard-rock mining and oilsands extraction, extreme high-speed wood cutting, and the manufacturing of composites for the aerospace industry, including hot-stages of thrust-vectoring nozzles. The repair welds that take a worn part and bring it back to its original shape have been demonstrated to be very effective, as they can improve the material properties beyond those of the original part, while also reducing the environmental impact. Two main technologies are used in this approach, one involving the deposition of layers (e.g. laser cladding), and another the buildup of 3D structures (e.g. additive manufacturing). However, as each part is unique, the process of making such repairs is currently labour intense, and new processes for 3D scanning and programming the welds are necessary to make the technology economically feasible for more industries. The project will develop novel techniques and processes to scan, program, and weld such parts. The complexities of the project stem from the required combination of part localization, identification and quantification of the damaged part with robust 3D reconstruction and comparison using 3D point-cloud data information, and the tool path planning based on the material behavior. The intrinsic properties of metals during the deposition process results in material transformations and residual stresses throughout the newly deposited material, which require a thorough investigation, and need to be taken into consideration in the toolpath planning. The goal is to create an automated system with Industry 4.0 capabilities that controls the process parameters for repair.