Pore structure and compressive properties of ADC12 porous aluminum fabricated by friction stir processing

Abstract

Recently, porous aluminum has attracted special interest as a new functional material. However, the application of porous aluminum remains limited due to high-cost fabrication and low productivity. To overcome these problems, the authors proposed a new fabrication method called the "FSP Friction Stir Processing route precursor method". In this study, using aluminum alloy die casting ADC12 as the starting material, porous aluminum is fabricated by the FSP route precursor method. At first, the pore structures of ADC12 porous aluminum are observed through X-ray CT. It is shown that, in the porous aluminum by FSP precursor method, the pore size distribution and the circularity of pores are similar to those in commercially available porous aluminum. Moreover, the compression tests for ADC12 porous aluminum and commercially available porous aluminum are carried out. It is shown that ADC12 porous aluminum indicates brittle fracture, and high plateau stress and high absorption energy comparing those of commercially available porous aluminum.

Effects of Porosity and Pore Structure on Compression Properties of Blowing-Agent-Free Aluminum Foams Fabricated from Aluminum Alloy Die Castings

“…The compression stress of all the ADC12 foams decreased after attaining the first peak stress, and thereafter slightly increased with indicating up and down of compression stress. This tendency was consistent with the stressstrain behavior of ADC12 foam fabricated using a blowing agent, 31) which is attributed to the eutectic nature of ADC12 aluminum alloy. The ADC12 foams had a higher plateau stress but a narrower plateau region than ALPORAS.…”

Effects of Amounts of Blowing Agent and Contained Gases on Porosity and Pore Structure of Porous Aluminum Fabricated from Aluminum Alloy Die Casting by Friction Stir Processing Route

“…4,5) Moreover, by adding 1 mass% of blowing agent to ADC12 containing a small amount of gases, porous aluminum with a porosity of approximately 70% was fabricated with comparatively large pores. 6,7) From these results, it is considered that, by effectively using both blowing agent and the gases contained in an aluminum alloy die casting, porous aluminum with higher porosity can be fabricated by adding a small amount of blowing agent and, moreover, the pore structure (i.e., the size and sphericity of pores) can be controlled by varying the amount of blowing agent. However, the effects of the amounts of blowing agent and gases contained in aluminum alloy die castings on the porosity and pore structure of porous aluminum have not been yet examined systematically.…”

“…Moreover, using various kinds of aluminum alloy plates as starting materials, we have investigated the conditions suitable for fabricating porous aluminum with high porosity and high quality (i.e., a uniform pore size distribution and highly spherical pores) by the FSP route precursor method. [4][5][6][7][8][9] In these attempts, it was found that when an aluminum alloy die casting was used as a starting material, the gases contained intrinsically in the die casting can be used to generate pores. Also, using ADC12 aluminum alloy die castings (called ''ADC12'' hereinafter) containing a large amount of gases, we fabricated porous aluminum of porosity up to 57% with small and highly spherical pores without the use of a blowing agent.…”

Plateau stress estimation of impact compression test on aluminum foam using X-ray computed tomography observation

“…2 shows the uniform A6061 Al foam specimen. Figure 3 shows a schematic illustration of the process of fabricating an FG Al foam precursor (Hangai et al, 2012a, Hangai et al, 2015, Utsunomiya et al, 2010b. As shown in Figs.…”

“…Moreover, to consider the applications of uniform and FG Al foams as shock absorbers of vehicles, the compressive behaviors of these foams have been studied through static and impact compression tests (Utsunomiya et al, 2010b, Hangai et al, 2015. As a characteristic of the compression stress-strain curve obtained by a compression test on Al foam, a plateau region with an approximately constant stress up to a large strain appears.…”