Laser beam joint welding of complex powder bed based additive manufactured components

使用激光熔化LBM(也称为选择性激光熔化，SLM)等附加制造工艺，可以制造出接近其最终尺寸的部件。这些制造工艺的一个主要优点是，可以实现用传统方法无法生产或只能以高昂成本生产的丝状和高度复杂的结构。该研究计划的目的是研究激光焊接在由AISI 316L和Inconel 718制造的LBM制造的部件上的应用。关于添加制造的部件之间的激光焊接接头的材料和结构特性的研究将分三个阶段进行。这三个阶段代表了加法生产的部件的三种不同程度的复杂性。要制定焊接策略，以保证简单到复杂的部件几何形状(如格子结构)的安全连接和焊接适宜性。在这个框架内，需要开发复杂的LBM制造的部件的安全连接的基本知识。在接下来的步骤中，还将检查沉淀硬化镍基合金的材料方面，目的是研究接头的微观结构及其影响。同时，还将了解LBM典型组织对焊接过程的影响。最后，将研究结果转化为一般的焊接策略和模型。与现有的确定T8/5冷却时间的方法类似，将考虑到LBM组件的导热系数、密度和复杂性，开发适用于添加组件的情况的方法。所申请的项目结果可以对LBM-典型组织和缺陷对材料导热系数的影响以及对焊接过程的影响提供基本的了解。这将为LBM制造的复杂部件的可靠连接提供基础，连接过程对材料性能的影响将主要针对一种具有代表性的沉淀硬化合金(Inconel 718)进行研究。

Components can be manufactured close to their final dimensions using additive manufacturing processes such as LBM for Laser Beam Melting (also known as Selective Laser Melting, SLM). A major advantage of these manufacturing processes is that filigree and highly complex structures can be realized that cannot be produced using conventional methods or can only be produced at great expense. The aim of the research proposal is to investigate the application of laser beam welding of LBM-manufactured components made of AISI 316L and Inconel 718.Findings on material and structure-specific properties of laser beam welded joints between additive manufactured components are to be developed in a three-stage approach. The three stages represent three different degrees of complexity of the additively produced components. Welding strategies are to be developed which can guarantee safe joints and the welding suitability of simple to complex component geometries (e.g. lattice structures).Within this framework, basic knowledge for the safe joining of complex LBM-manufactured components is to be developed. In a subsequent step, the material aspect of a precipitation-hardening nickel-based alloy will also be examined with the aim of investigating the microstructure of the joint and its influenceability. At the same time, an understanding of the influence of the LBM-typical microstructure on the welding process will be created. Finally, the findings will be transferred into general welding strategies and models. In analogy to existing approaches regarding the determination of t8/5 cooling times, approaches for the case of additive components will be developed, taking into account the thermal conductivity, density and complexity of the LBM component. The results of the project applied for can provide a basic understanding of the influence of LBM-typical microstructures and defects on the thermal conductivity of the materials and the effect on the welding process. This will provide the basis for the reliable joining of complex LBM-manufactured components and the influence of the joining process on the material properties will be developed primarily on a representative, precipitation-hardening alloy (Inconel 718).