Evolution of internal pores within AlSi10Mg manufactured by laser powder bed fusion under tension: As-built and heat treated conditions
Evolution of internal pores within AlSi10Mg manufactured by laser powder bed fusion under tension: As-built and heat treated conditions
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DOI：
10.1016/j.matdes.2021.109645
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发表时间：
2021-03
影响因子：
8.4
通讯作者：
J. Hastie;Joachim Koelblin;M. Kartal;Moataz M. Attallah;R. Martínez
中科院分区：
文献类型：
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作者：
J. Hastie;Joachim Koelblin;M. Kartal;Moataz M. Attallah;R. Martínez
近年来，激光粉末床熔合（LPBF）制备高致密AlSi 10 Mg零件的工艺参数优化受到了相当大的关注。尽管如此，重要的是要考虑在真实的世界应用中可能存在的建成大孔隙，例如，由于可用LPBF系统的限制、与产生近乎完美的密度相关的时间和成本限制等。在这项工作中，回收的粉末用于制造AlSi10Mg试样，通过LPBF进行最佳致密化，并对在增加拉伸载荷下发生的试样孔隙率的演变进行了实验研究。采用高分辨率X射线微计算机断层扫描（XμCT）结合原位微测试平台，获取不同加载阶段的三维图像。在竣工条件下和热等静压（HIP）或T6 HIP后对样本进行测试。建成孔隙度没有显着变化，导致脆性断裂。韧性HIPped试样内的孔隙均匀伸长的损伤传播和孔隙合并的发病。在小的拉伸下，孔的形状发生了很大的变化，而体积没有变化。就失效前观察到的孔隙改性程度而言，热等静压处理加T6在竣工和热等静压处理条件之间产生了折衷。
The optimisation of processing parameters to produce high densification AlSi10Mg parts by laser powder bed fusion (LPBF) has received considerable attention in recent years. Nonetheless, it is important to consider the potential presence of as-built large pores in real world applications,e.g.due to limitations of the available LPBF system, time and cost constraints associated with producing near-perfect density and so on. In this work, recycled powder was used to fabricate AlSi10Mg specimens with sub-optimal densification by LPBF and an experimental investigation into the evolution of specimen porosity occurring under increasing tensile load was performed. A combination of high-resolution X-ray micro computed tomography (XμCT) and anin-situmicro-testing stage was employed to acquire 3D images at different loading stages. Specimens were tested in the as-built condition and following hot isostatic pressing (HIPping) or HIPping with T6. As-built porosity did not change markedly in the lead-up to brittle-like fracture. Pores within ductile HIPped specimens were uniformly elongated up to the onset of damage propagation and pore coalescence. Pore shape change occurred largely without volume change at small extension. HIPping plus T6 produced a compromise between as-built and HIPped conditions in terms of the extent of pore modification observed prior to failure.