Nondestructive Observation of Pore Structures of A1050 Porous Aluminum Fabricated by Friction Stir Processing

Abstract

In the automotive industry, porous aluminum is expected to be used as a new functional material because of its light weight, high energy absorption and high sound-insulating property. Recently, a new processing route for fabricating the porous aluminum precursor, which utilizes friction stir processing (FSP), has been developed. It is expected that, by applying the FSP route precursor method, the cost-effective fabrication of porous aluminum with high productivity can be realized. In this study, two different types of A1050 porous aluminum were fabricated from two different sizes of precursor by the FSP route precursor method. The two types of porous aluminum fabricated using small and large precursors are hereafter referred to ''FSP-S porous aluminum'' and ''FSP-L porous aluminum'', respectively. The pore structures of FSP-S porous aluminum, FSP-L porous aluminum and also commercially available porous aluminum (ALPORAS, fabricated by Shinko Wire Co., Ltd.) were nondestructively observed by X-ray computed tomography (X-ray CT). From the nondestructive observation of pore structures, it was shown that a large number of pores of smaller area and volume were distributed in porous aluminum fabricated by the FSP route precursor method compared with the pores in ALPORAS. However, there was little difference in the circularity of pores between porous aluminum fabricated by the FSP route and ALPORAS, and there was little dependence of the pore structure on the precursor size for porous aluminum fabricated by the FSP route. This result indicates the potential of the FSP route for fabricating larger porous aluminum samples.

Fabrication and Tensile Tests of Aluminum Foam Sandwich with Dense Steel Face Sheets by Friction Stir Processing Route

“…It can be seen that the AFS can be obtained with a good bonding interface and good pore structures by FSP route. The average pore diameter observed from the X-ray CT image was 2.67 mm, which was almost the same as that of A1050 aluminum foam fabricated by FSP route without dense steel sheets 14) and smaller than that of ALPORAS 15) manufactured by Shinko Wire Co., Ltd. (Amagasaki, Japan). Figure 3 shows the typical microstructure of the bonding interface.…”

Gaining new insights into nanoporous gold by mining and analysis of published images

“…Meeting these criteria does not require significant additional effort, given access to standard materials research equipment, such as a scanning electron microscope with elemental analysis capabilities. Although we are unaware of published data in the field of nanoporous metals demonstrating significant inaccuracies in using 2D over 3D images to gather quantitative structural information, there is evidence that 2D measurements are accurate in comparison to 3D measurements in metallic foams 58 . It would be useful to quantify this relationship in nanoporous metals and other complex structures due to the popularity of 2D analysis in metallic foams and other cellular materials 59 .…”

Quantitative X-ray tomography

“…Others have focussed on the pore size distribution. [230][231][232][233] In Ref. 234 this distribution was measured over several length scales using a suite of 3D imaging methods (X-ray CT, focussed ion beam serial sectioning, electron tomography) and is compared with Mercury intrusion measurements.…”