Characterization and quantification of mechanisms influencing the process reliability of Laser Beam Melting by experimental and numerical investigations

通过实验和数值研究对影响激光束熔化工艺可靠性的机制进行表征和量化

• 批准号: 387081806
• 负责人: Professor Dr.-Ing. Nikolaus Andreas Adams
• 金额: --
• 依托单位: Lehrstuhl für Aerodynamik und Strömungsmechanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387081806?language=en
• 关键词: Characterization; quantification; mechanisms; influencing; process

The aim of the proposed research project is an advancement of the knowledge on additive manufacturing processes, which employ lasers beams for melting metal powders. The planned investigations will consider the process of cooling and solidification of the molten metal as well as the evaporation of liquid metal, which influences process characteristics and product quality, especially with respect to the occurrence of pores. Also thermally induced residual stresses in vicinity of the heating zone will be analyzed. The focus of the proposed project will be the analysis of the interactions between on one side the selected process parameters (e.g. laser power, scanning speed), the materials employed (heat conductivity, enthalpies of phase changes, powder particle size and shape) and on the other side the fluid- and thermodynamic effects in the melt pool (convection, Marangoni-effect, evaporation, liquid surface topology and laser beam reflections etc.). The obtained insights will allow for more stable beam melting processes and also help to reduce reject rates in production, reduce the number of test runs for new part designs and also allow to shorten the testing program when qualifying new materials.Initially an experimental process analysis is conducted in order to estimate the extent of influence of major process parameters on the process stability. In the following the mechanisms of interaction are investigated in greater detail and are also quantified employing experiments as well as numerical simulations. For the first time the method of smoothed particle hydrodynamics (SPH) will be applied for the simulation of laser beam melting. With SPH fluids and solids are described by Lagrangian particles, which carry properties of the respective phase. Local macroscopic values, such as temperature, are recovered by averaging operations using all particles in vicinity of the position considered. Judging by todays state of technology and our preliminary work, SPH methods will allow for a highly efficient handling of multiple phase changes and of powder layers featuring complex geometries. This will enable simulations of laser beam melting taking into account all relevant physical mechanisms. Experimental investigations will be conducted to validate the numerical method and broaden the knowledge on the melting process. In order to adequately capture rapid transient processes, suitable measurement techniques will be evaluated and adopted to the problem. For investigations of melt pool dynamics and also of the blow-away effect of powder particles from the heating zone due to application of shielding gases and also due to evaporation of the melt, high-speed cameras will be employed.

拟议的研究项目的目的是进步有关添加剂制造过程的知识，这些过程采用激光束进行熔化的金属粉末。计划的研究将考虑熔融金属冷却和固化的过程以及液体金属的蒸发，这影响了过程特征和产品质量，尤其是在孔隙发生的情况下。还将分析加热区附近的热诱导残留应力。 The focus of the proposed project will be the analysis of the interactions between on one side the selected process parameters (e.g. laser power, scanning speed), the materials employed (heat conductivity, enthalpies of phase changes, powder particle size and shape) and on the other side the fluid- and thermodynamic effects in the melt pool (convection, Marangoni-effect, evaporation, liquid surface topology and laser beam reflections etc.).获得的见解将允许更稳定的光束熔化过程，还有助于降低拒绝率，减少新零件设计的测试运行次数，并在合格的新材料时缩短测试程序。进行新的实验过程分析，以估计主要过程参数对过程稳定性的影响程度。在以下内容中，对相互作用的机制进行了更详细的研究，并通过实验和数值模拟进行了量化。首次将平滑颗粒流体动力学（SPH）的方法应用于激光束熔体的模拟。 Lagrangian颗粒具有SPH流体和固体，这些颗粒具有各个相的特性。局部宏观值（例如温度）是通过使用所考虑位置附近的所有粒子平均操作来恢复的。从今天的技术状态和我们的初步工作来看，SPH方法将允许对多个相变的高效处理以及具有复杂几何形状的粉末层。这将考虑到所有相关物理机制的激光束融化模拟。将进行实验研究以验证数值方法并扩大有关熔化过程的知识。为了充分捕获快速的瞬态过程，将评估并通过该问题来评估合适的测量技术。为了研究熔体池动力学以及由于屏蔽气体的应用以及由于熔融液的蒸发而导致的粉末颗粒的吹动效应，也将采用高速摄像头。

项目成果

A Smoothed Particle Hydrodynamics Model for Laser Beam Melting of Ni-based Alloy 718

• DOI: 10.1016/j.camwa.2018.10.020
• 发表时间: 2019-10
• 期刊: Comput. Math. Appl.
• 作者: Johannes Weirather;V. Rozov;Mario Wille;Paul Schuler;C. Seidel;N. Adams;M. Zaeh

Experimental and Numerical Investigations of In Situ Alloying during Powder Bed Fusion of Metals Using a Laser Beam

• DOI: 10.3390/met11111842
• 发表时间: 2021-11
• 期刊: Metals
• 影响因子: 2.9
• 作者: A. Wimmer;B. Yalvac;C. Zoeller;Fabian Hofstaetter;S. Adami;N. Adams;M. Zaeh

In situ alloying: investigation of the melt pool stability during powder bed fusion of metals using a laser beam in a novel experimental set-up

• DOI: 10.1007/s40964-021-00233-y
• 发表时间: 2021-10-31
• 期刊: PROGRESS IN ADDITIVE MANUFACTURING
• 作者: Wimmer, Andreas;Hofstaetter, Fabian;Zaeh, Michael F.
• 通讯作者: Zaeh, Michael F.

Analysis of the phase transformation of AlSi10Mg during Laser Powder Bed Fusion

激光粉床熔融过程中 AlSi10Mg 的相变分析

• DOI: 10.1016/j.procir.2020.09.034
• 发表时间: 2020
• 期刊: Procedia CIRP
• 作者: Wimmer;Lehmann;Schuler
• 通讯作者: Schuler