Manufacturing and Investigation of In Situ and Ex Situ Produced Aluminum Matrix Foam‐Filled Tubes

Abstract

Composite metal foams (CMFs) are hybrid structures, which are usually produced from separate parts, and not in one step as functional, structural elements. Functional CMFs are characterized by high strength, high stiffness, and extreme energy absorbing properties compared with conventional metallic foams, which allow them to be used as load‐bearing and energy absorbing elements. Test specimens are made in AlMgSi0.5 tubes with the wall thickness of 5 mm. AlSi12 casting alloy is used as matrix material. To ensure the foam structure porosity, lightweight expanded clay aggregate particles (LECAPs) are used with unimodal and bimodal size distribution. The results show that low‐cost unimodal and bimodal foam‐filled tubes (FFTs) can be produced in situ by inert gas pressure infiltration. Besides their low density, these CMFs achieve high strength, high toughness, and special, functional properties compared with simple metallic foams. After heat treatment, in situ produced bimodal FFTs have the highest energy absorption capacity of an average of 67.2 J cm−3, which is 9% higher than the average value of the ex situ FFTs. Therefore, it is advantageous to produce in situ FFTs, because with proper manufacturing, it requires less machining, making the production easier, while achieving better compressive properties.

The Effects of Various Adhesives on Multiple Types of Quasi‐Static Mechanical Properties of Rectangular and Square Aluminum Hollow Sections Filled with Composite Metal Foam Cores

“…During each type of measurement, the CFFHS structures significantly had higher strength and energy absorption than CMFs, especially during the bend tests, making lightweight CMF core structures applicable as components with not purely axial Figure 10. Specific energy absorption of various FFHSs under axial compression at ambient temperature, obtained from research articles, [7,8,[10][11][12][13][14]16,20,21,[24][25][26][27][28][29][30][35][36][37][38][39][40] compared to the CFFHSs developed in this research. Note: the specific energy absorption was calculated up to 0.5 strain if not shown otherwise on the diagram.…”

“…The fabrication of these structures can be defined based on the manufacturing steps as in situ or ex situ. In situ metal FFTs are produced in one step; [ 7–9 ] the foam manufacturing process takes place in the tube, while during the ex situ method, the metal foam is machined to an appropriate size after production and then placed or fixed into a tube.…”

“…The fabrication of these structures can be defined based on the manufacturing steps as in situ or ex situ. In situ metal FFTs are produced in one step; [7][8][9] the foam manufacturing process takes place in the tube, while during the ex situ method, the metal foam is machined to an appropriate size after production and then placed or fixed into a tube.Most articles are on the axial compressive properties of ex situ produced circular FFTs with aluminum or aluminum alloy closed-cell foam cores. Either aluminum alloy [10][11][12][13] or steel [14,15] outer tubes were examined.…”

B4C‐Reinforced Al–Zn Foams Having Superior Energy Absorption Efficiency

“…It should be noted that most of the systems discussed in the literature (Figure 13) were produced via the melt route. [43,50,63,64] Further, the addition of B 4 C particles could have increased the collapsible strength of the cells and delayed the cell wall collapse, leading to better energy absorption capacity. [57,65,66] However, it is difficult to make a one-to-one comparison due to the different foaming routes and processing parameters employed in various studies.…”

New Aluminum Syntactic Foam: Synthesis and Mechanical Characterization

“…Orbulov et al showed that using EC nodules could reduce economic costs and potentially synthesize ASFs for the transport industry [ 23 ]. Subsequently, Kemeny et al and Leveles et al [ 24 , 25 , 26 ] demonstrated that using EC-ASF (AlSi12) as filler of an AlMgSi0.5 tube (ASF-FFT) improves the compressive performance. Furthermore, it was found that ex-situ filled tubes and bimodal ASF-FFT embedding EC in different sizes (2.5–3 and 3.5–4 mm) with the same volume ratio enhance the mechanical properties.…”