Fabrication and Mechanical Properties of Rolled Aluminium Unidirectional Cellular Structure

• Main Authors: Matej Vesenjak, Masatoshi Nishi, Toshiya Nishi, Yasuo Marumo, Lovre Krstulović-Opara, Zoran Ren, Kazuyuki Hokamoto
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Metals
• Subjects: unidirectional cellular structure; porosity; fabrication; explosive compaction; metallography; computational simulation
• Online Access: https://www.mdpi.com/2075-4701/10/6/770

The paper focuses on the fabrication of novel aluminium cellular structures and their metallographic and mechanical characterisation. The aluminium UniPore specimens have been manufactured by rolling a thin aluminium foil with acrylic spacers for the first time. The novel approach allows for the cheaper and faster fabrication of the UniPore specimens and improved welding conditions since a lack of a continuous wavy interface was observed in the previous fabrication process. The rolled assembly was subjected to explosive compaction, which resulted in a unidirectional aluminium cellular structure with longitudinal pores as the result of the explosive welding mechanism. The metallographic analysis confirmed a strong bonding between the foil surfaces. The results of the quasi-static and dynamic compressive tests showed stress–strain behaviour, which is typical for cellular metals. No strain-rate sensitivity could be observed in dynamic testing at moderate loading velocities. The fabrication process and the influencing parameters have been further studied by using the computational simulations, revealing that the foil thickness has a dominant influence on the final specimen geometry.