Cold spraying of tailored aluminium foam precursors: Investigating the correlation between spraying conditions and foam morphology

• Published in: Journal of manufacturing processes Vol. 127; pp. 477 - 487
• Main Authors: Perna, A.S., Viscusi, A., Astarita, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.10.2024
• Subjects: Aluminium foam; Closed-cells morphology; Cold spray parameters; Gradient porosity; Precursor density; Gradient porosity; Cold spray parameters; Aluminium foam; Precursor density; Closed-cells morphology
• ISSN: 1526-6125
• DOI: 10.1016/j.jmapro.2024.08.016

Tailoring the precursor of metal foams could be significantly challenging, and the conventional precursor manufacturing techniques limit the creation of complex three-dimensional foamed structures. The aim of this paper is to prove the effectiveness of cold spray in producing tailored aluminium foam precursors, with the final goal of producing precursors for foamed structures with a desired gradient of cell morphology in a single step process and by using the same feedstock material. The key idea is to produce precursors by the spraying of a feedstock material made of a mixture of foaming agent and aluminium, with a given density, and to study the correlation between the density of the precursor and the features of the foamed structure. The density of the precursor is determined by the spraying conditions, hence varying the spraying parameters, it is possible to diversify the properties of the foam. In this paper, precursors with three different densities have been produced by using the same feedstock but varying the standoff distance and the gas temperature, then all the three samples have been allowed to foam in an oven simultaneously under the same conditions. Detailed analyses have been conducted to characterize the foams, revealing that the initial density governs the foam structure. Hence, adjusting the spraying parameters allows for the manufacture of precursors with diverse characteristics, enabling the production of foams with varying cell sizes.