The formability of aluminum foam sandwich panels
The formability of aluminum foam sandwich panels
复制标题
泡沫铝夹芯板的成型性能
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
G. Maccarini
中科院分区：
文献类型：
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作者：
G. D’Urso;G. Maccarini
本文旨在研究泡沫铝夹层板（AFS）的成形性。目前，发泡装置的最终形状是直接通过发泡过程本身获得的，不需要进一步的成型步骤。在任何情况下，进一步的制造工艺可以用来生产更复杂的零件。在成形工序中，弯曲是研究和应用最简单的工序之一。此外，弯曲试验可能产生有关材料特性的有趣信息。在金属泡沫表征方面，通过改变工艺条件，对Alulight®制造的AFS板进行了多次弯曲测试。为此目的，使用了通用试验机，收集有关变形几何形状和有关载荷与位移的数据。尽管试样的变形与泡沫细胞的破坏或坍塌有关，但一旦该过程终止，它们仍然保持着显著的抗弯强度。采用非破坏性和力学试验对金属泡沫的性能进行了研究。特别是，在进行镦粗和弯曲试验之前，对AFS试样进行了厚度测量（使用超声波探测仪）、x射线分析和泡沫密度测量。对泡沫弯曲过程进行了有限元模拟，研究了试样的应力和应变分布。利用有限元软件Deform 2D建立了弯曲过程的等温平面应变模型。该研究结果用于通过组合三个90°弯头来生产封闭结构组件（方形）。进一步的改进包括连接开口端，以提高抗剪和抗扭能力。在连接技术中，研究了传统的焊接方法（钨惰性气体tig和激光）和非传统的方法（搅拌摩擦焊- fsw）。最后，采用三点和四点弯曲试验对接头的力学性能进行了表征。
The present paper aims to study the formability of Aluminum Foam Sandwich (AFS) panels. At now, the final shape of foamed devices is directly obtained through the foaming process itself and no further shaping steps are expected. In any case, further manufacturing processes may be exploited to produce more complex parts. Among forming operations, bending can be regarded as one of the simplest processes for both study and application. Besides, bending tests may yield interesting information about material properties. With regard to the metal foams characterization, several bending tests on AFS panels fabricated by Alulight® were carried out by varying the process conditions. A universal testing machine was employed for this purpose, collecting data about the deformed geometry and about load vs. displacement. Even though the samples deformation was related to the occurrence of foam cells failure or collapse, once the process was terminated, they still retained a significant bending strength. The metal foams properties were also investigated using both non-destructive and mechanical tests. In particular, thickness measurements (using an ultrasonic feeler), X-ray analysis and foam density measurements were carried out on AFS specimens before the execution of both upsetting and bending tests. Finite Element simulations of the foam bending process were performed to investigate stress and strain distributions on the specimens. In particular, an isothermal plane strain model of the bending process was setup using the FEM commercial code Deform 2D. The results of this study were used to produce closed structure components (square shapes) by combining three 90° bends. A further improvement consisted in joining the open ends, to enhance shear and torsion resistance. Among joining techniques conventional welding processes (Tungsten Inert Gas—TIG and laser) and a non-conventional method (Friction Stir Welding—FSW) were investigated. Finally, the mechanical properties of the joints were characterized using both three and four point bending tests.