Purpose

Support structures used in laser powder bed fusion are often difficult to clean from unsintered powder at the end of the process. This issue can be significantly reduced through a proper design of these auxiliary structures. This paper aims to investigate preliminary the airflow within differently oriented support structures and to provide design guidelines to enhance their cleanability, especially the depowdering of them.

Design/methodology/approach

This study investigates the cleanability of support structures in powder bed fusion technology. Digital models of cleaning operations were designed through computer-aided engineering systems. Simulations of the airflow running into the powder entrapped within the thin walls of auxiliary supports were implemented by computational fluid dynamics. This approach was applied to a set of randomly generated geometrical configurations to determine the air turbulence intensity depending on their design.

Findings

The results, which are based on the assumption that a relationship exists between turbulence and powder removal effectiveness, demonstrated that the maximum cleanability is obtainable through specific relative rotations between consecutive support structures. Furthermore, it was possible to highlight the considerable influence of the auxiliary structures next to the fluid inlet. These relevant findings establish optimal design rules for the cleanability of parts manufactured by powder bed fusion processes.

Originality/value

This study presents a preliminary investigation into the cleanability of support structures in laser powder bed fusion, which has not been addressed by previous literature. The results allow for a better understanding of the fluid dynamics during cleaning operations. New guidelines to enhance the cleanability of support structures are provided based on the results of simulations.

中文翻译：

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粉末床融合技术生产支撑结构可清洁性的数值研究

目的

激光粉末床融合中使用的支撑结构通常难以在过程结束时从未烧结的粉末中清除。通过适当设计这些辅助结构，可以显着减少这个问题。本文旨在初步研究不同方向支撑结构内的气流，并提供设计指南以提高其可清洁性，尤其是它们的去粉化。

设计/方法/方法

本研究调查了粉末床融合技术中支撑结构的可清洁性。清洁操作的数字模型是通过计算机辅助工程系统设计的。通过计算流体动力学实现了气流进入辅助支撑薄壁内夹带的粉末的模拟。这种方法应用于一组随机生成的几何配置，以确定根据其设计的空气湍流强度。

发现

结果基于湍流和粉末去除效率之间存在关系的假设，表明通过连续支撑结构之间的特定相对旋转可以获得最大的清洁度。此外，可以突出流体入口旁边的辅助结构的显着影响。这些相关发现为粉末床熔融工艺制造的零件的可清洁性建立了最佳设计规则。

原创性/价值

本研究对激光粉末床融合中支撑结构的可清洁性进行了初步调查，以前的文献尚未对此进行讨论。结果允许更好地了解清洁操作期间的流体动力学。根据模拟结果提供了增强支撑结构可清洁性的新指南。