Purpose

A key challenge found in additive manufacturing is the difficulty to produce components with replicable microstructure and mechanical performance in distinct orientations. This study aims to investigate the influence of build orientation on the fracture toughness of additively manufactured AlSi10Mg specimens.

Design/methodology/approach

The AlSi10Mg specimens were manufactured using the selective laser melting (SLM) technology. The fracture toughness was experimentally determined (under ASTM E399-09) using C(T) specimens manufactured in different orientations. The microstructure of the specimens was examined using metallography to determine the effects of grain orientation on fracture toughness.

Findings

The fracture toughness magnitude of manufactured specimens ranged between 36 and 50 MPam, which closely matched conventional bulk material and literature values regarding AlSi10Mg components. The C(T) specimens printed in the T-L orientation yielded the highest fracture toughness. The grain orientation and fracture toughness values confirm the anisotropic nature of SLM parts where the T-L-oriented specimen obtained the highest K_IC value. A clear interaction between the melt pool boundaries and micro-slipping during the loading application was observed.

Originality/value

The novelty of this paper consists in elucidating the relationship between grain orientation and fracture toughness of additively manufactured AlSi10Mg specimens because of the anisotropy generated by the different melting pool boundaries and orientations in SLM. The findings show that melt pool boundaries can behave as easier pathways for cracks to propagate and subsequently reduce the fracture toughness of specimens with cracks perpendicular to the build direction.

中文翻译：

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堆焊方向对选择性激光熔炼AlSi10Mg断裂行为的影响

目的

在增材制造中发现的关键挑战是难以生产具有可复制的微观结构和在不同方向上具有机械性能的组件。这项研究的目的是调查构造方向对添加制造的AlSi10Mg试样的断裂韧性的影响。

设计/方法/方法

AlSi10Mg样品是使用选择性激光熔化（SLM）技术制造的。使用在不同方向上制造的C（T）样品通过实验确定断裂韧性（根据ASTM E399-09）。使用金相学检查样品的微观结构，以确定晶粒取向对断裂韧性的影响。

发现

制成的试样的断裂韧性值在36至50 MPam之间，与常规的散装材料和有关AlSi10Mg组分的文献资料非常接近。以TL方向打印的C（T）试样具有最高的断裂韧性。晶粒取向和断裂韧性值证实了SLM零件的各向异性，其中TL取向试样获得了最高的K _IC值。观察到在加载过程中熔池边界和微滑移之间存在明显的相互作用。

创意/价值

本文的新颖之处在于阐明了增材制造的AlSi10Mg试样的晶粒取向与断裂韧性之间的关系，这是由于SLM中不同熔池边界和取向所产生的各向异性。研究结果表明，熔池边界可以作为裂纹扩展的更容易途径，从而降低垂直于生成方向的裂纹试样的断裂韧性。