Simulation based process analysis of the powder bed additive manufacturing process Selective Laser Melting (SLM)

基于仿真的粉末床增材制造工艺选择性激光熔化 (SLM) 工艺分析

• 批准号: 418105836
• 负责人: Professor Dr.-Ing. Johannes Henrich Schleifenbaum, since 12/2019
• 金额: --
• 依托单位: Fraunhofer-Institut für Lasertechnik (ILT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/418105836?language=en
• 关键词: Simulation; based; process; analysis; powder

Laser based Additive Manufacturing technologies such as powder bed based selective laser melting allow an almost unlimited geometrical freedom in the production of metallic functional parts. Due to existing process deficits like residual stresses and part distortion this immense potential for the production of functional parts of high complexity can be exploited in a limited way only. This is caused by the currently insufficient understanding of the involved physical processes both locally in the interaction or process zone (e.g. beam propagation in the powder layer, evaporation) and globally in the part (thermomechanics). Neither part nor specific to material there are currently concrete recommendation regarding a stress or distortion minimizing process management. The scientific benefits of the project is given by the development of a multiscale simulation of the SLM process, which reduces the computation time for a thermomechanical simulation by using multiscale methods and parallelized algorithms. By the computational prediction of distortion and residual stresses a gained understanding of the process will help to identify process strategies for stress and distortion-minimizing production. The aim of this project is to reduce the number of degrees of freedom (factor 1,000-10,000) required for simulations of parts by means of multiscale approaches, thus realizing a macro-simulation of the process in which the welding sequence, the supporting structures and process parameters are taken into account. Further development of an existing model for the process zone (meso-scale) which allows a sufficiently accurate calculation of the temperature fields in acceptable computation times (<1h) is necessary for the construction of the multiscale simulation. The calculated temperature-time cycles are the input for a multiscale simulation for the thermomechanical processes of parts. Based on the gained understanding of the process the relevant process variables will be identified and experimental process strategies for stress and distortion-minimizing production will be developed and validated using relevant parts.

基于激光的添加剂制造技术（例如粉末床的选择性激光熔化）在生产金属功能零件时几乎无限的几何自由。由于现有的过程缺陷，例如残留应力和部分变形，因此只能以有限的方式利用高复杂性功能部分的巨大潜力。这是由于当前对相互作用或过程区域中局部局部物理过程的理解不足（例如，粉末层中的束传播，蒸发）和全球（热力学）的全球范围。目前既没有部分材料的部分，也没有针对压力或失真最小化过程管理的具体建议。该项目的科学益处是通过开发SLM过程的多尺度模拟来给出的，该过程通过使用多尺度方法和并行化算法来减少热机械模拟的计算时间。通过对失真和残留应力的计算预测，对过程的了解将有助于确定压力和变形最小化产量的过程策略。该项目的目的是减少通过多尺度方法模拟零件所需的自由度（因子1,000-10,000）的数量，从而意识到对焊接顺序，支持结构和过程参数的过程进行宏观模拟。进一步开发了过程区域（中尺度）现有模型，该模型允许在可接受的计算时间（<1H）中足够准确地计算多尺度模拟的温度场（<1H）。计算出的温度时间循环是用于零件热机械过程的多尺度模拟的输入。基于对过程的了解，将确定相关的过程变量，并将使用相关零件制定和验证压力和最小化生产的实验过程策略。