The Influence of Machining Parameters on the Surface Porosity of a Closed-Cell Aluminium Foam

Abstract

Aluminium foam elements foamed into moulds, have a porous core, surrounded by a thin layer of non-porous outer surface. This layer affects the homogeneity and mechanical properties of the element significantly. To produce functional elements, the foams can be machined to a desired end shape. Machining deforms the surface structure, which results in a reduction of strength properties. This article describes an experimental approach to determine the effects of machining parameters on the surface porosity of closed-cell aluminium foam samples. The samples were machined by incremental forming and friction rolling with precisely defined processing parameters (deformation depth, feed rate and spindle speed). High-resolution digital photos of the treated surfaces were taken and analysed using image segmentation with a multispectral threshold algorithm. The change of surface porosity was calculated for each sample, and the influence of the selected machining parameters was determined by the use of response surface methodology. The optimal machining parameters are presented.

Determination of the Grain Size in Single-Phase Materials by Edge Detection and Concatenation

“…Further application of the proposed edge extraction algorithm in other similar problems is encouraged, to evaluate further the algorithm's usability. The authors encourage the use of developed methods in macroscopical problems, such as determination of aluminium foam cells size [21] and similar ones in the Image Processing and Measurements domain [22]. The authors also encourage further assessment of BE and BE+ robustness, since these two simple procedures were only tested on 20 sample images overall.…”

Numerical and Experimental Study of Quasi-Static Loading of Aluminum Closed-Cell Foams Using Weaire–Phelan and Kelvin Tessellations

“…Metallurgical and morphological (Zhu et al 2018;Yilbas et al 2014Yilbas et al , 2013Yilbas et al , 2015 observations have revealed that cutting process affects porous material's mechanical properties significantly. Various processing and machining parameters such as deformation depth, feed rate, spindle speed (Razboršek et al 2019) in incremental forming and frictional rolling method as well as laser power, scanning speed, gas pressure, cutting forces, and cutting temperatures (Liu et al 2020) in laser cutting techniques have been previously investigated thoroughly. For instance, Heidari and Yan used single-crystal diamond tools for cutting, and realized that the presence of pores affects the accuracy of cutting mechanism directly (Heidari and Yan 2018).…”