A new filler material is presented and tested to produce light-weight aluminium alloy composites: the pore space between nano-structured silica-aerogel granulates is infiltrated with Al-alloy melts. Since these filler materials have vanishing density (100 kg m−3), they need not to be removed from the final cast product. Their shape, size and volume fraction determine the materials’ properties. Different methods were used to prepare metal-aerogel syntactic foam composites: centrifugal casting, squeeze and suction casting. The last method gave the best results, using an Al–11Si melt. We produced circular and rectangular bars up to 500-mm length. The composite material has a density of around 900 kg m−3, a yield stress of 8 MPa and absorbs 8 kJ kg−1 mechanical energy.
BanhartJ.: ‘Manufacture, characterisation and application of cellular metals and metal foams’, Prog. Mater. Sci., 2001, 46, 559–632. doi: 10.1016/S0079-6425(00)00002-5
2.
MondalD. P., DasS., RamakrishnanN. and BhaskerK. U.: ‘Cenosphere filled aluminum syntactic foam made through stir-casting technique’, Composites Part A, 2009, 40, (3), 279–288. doi: 10.1016/j.compositesa.2008.12.006
3.
GoelM. D., MondalD. P., YadavM. S. and GuptaS. K.: ‘Effect of strain rate and relative density on compressive deformation behavior of aluminum cenosphere syntactic foam’, Materi. Sci. Eng.: A, 2014, 590, (C), 406–415. doi: 10.1016/j.msea.2013.10.048
4.
BaumeisterJ., BanhartJ. and WeberM.: ‘Aluminium foams for transport industry’, Mater. Des., 1998, 18, 217–220. doi: 10.1016/S0261-3069(97)00050-2
5.
BaumeisterJ., WeiseJ., HirtzE., HöhneK. and HoheJ.: ‘Applications of aluminum hybrid foam sandwiches in battery housings for electric vehicles’, Procedia Mater. Sci., 2014, 4, 301–305. doi: 10.1016/j.mspro.2014.07.565
6.
FugantiA., LorenziL. and HanssenA. G.: ‘Aluminium foam for automotive applications’, Adv. Eng. Mater., 2000, 2, (4), 200–204. doi: 10.1002/(SICI)1527-2648(200004)2:4<200::AID-ADEM200>3.0.CO;2-2
7.
MiyoshiT., ItohM., AkiyamaS. and KitaharaA.: ‘Alporas aluminum foam: production process, properties, and applications’, Adv. Eng. Mater., 2000, 2, (4), 179–183. doi: 10.1002/(SICI)1527-2648(200004)2:4<179::AID-ADEM179>3.0.CO;2-G
8.
PalmerR. A., GaoK., DoanT. M., GreenL. and CavallaroG.: ‘Pressure infiltrated syntactic foams—process development and mechanical properties’, Mater. Sci. Eng.: A, 2007, 464, (1–2), 85–92. doi: 10.1016/j.msea.2007.01.116
9.
PeroniL., ScapinM., AvalleM., WeiseJ. and LehmhusD.: ‘Dynamic mechanical behavior of syntactic iron foams with glass microspheres’, Mater. Sci. Eng.: A, 2012, 552, 364–375. doi: 10.1016/j.msea.2012.05.053
10.
OrlovI. N.: ‘Compressive properties of aluminium matrix syntactic foams’, Mater. Sci. Eng.: A, 2012, 555, 52–56. doi: 10.1016/j.msea.2012.06.032
11.
MajlingerK. and OrlovI. N.: ‘Characteristic compressive properties of hybrid metal matrix syntactic foams’, Mater. Sci. Eng.: A, 2014, 606, (C), 248–256. doi: 10.1016/j.msea.2014.03.100
12.
OrlovI. N.: ‘Metal matrix syntactic foams produced by pressure infiltration—the effect of infiltration parameters’, Mater. Sci. Eng.: A, 2013, 583, (C), 11–19. doi: 10.1016/j.msea.2013.06.066
13.
OrlovI. N. and GinsztlerJ.: ‘Compressive characteristics of metal matrix syntactic foams’, Composites Part A, 2012, 43, (4), 553–561. doi: 10.1016/j.compositesa.2012.01.008
14.
LehmhusD., WeiseJ., BaumeisterJ., PeroniL., ScapinM., FicheraC., AvalleM. and BusseM.: ‘Quasi-static and dynamic mechanical performance of glass microsphere- and cenosphere-based 316l syntactic foams’, Procedia Mater. Sci., 2014, 4, 364–368. doi: 10.1016/j.mspro.2014.07.578
15.
PoulsonT., WeiseJ., BaumeisterJ., HolbergS., PrimdahlD. S. and ZangenbergN.: ‘Syntactic aluminum foams produced from coated glass sphere preforms’ in ‘Cellmat 2012’, (ed. C. C. GmbH), Jena: www.conventus.de, 1–4; 2012.
16.
BanhartJ.: ‘Aluminium foams: on the road to real applications’, MRS Bull., 2003, 28, 290–295. doi: 10.1557/mrs2003.83
17.
AlkemperJ., RatkeL. and DiefenbachS.: ‘Chill casting into aerogels’, Scripta Metall. Mater., 1993, 29, 1495–1500. doi: 10.1016/0956-716X(93)90343-Q
18.
AlkemperJ., BuchholzT., MurakamiK. and RatkeL.: ‘Solidification of aluminium alloys in aerogel moulds’, J. Non-Cryst. Solids, 1995, 186, 395–401. doi: 10.1016/0022-3093(95)00060-7
19.
AlkemperJ., SousS., StöckerC. and RatkeL.: ‘Directional solidification in an aerogel furnace with high resolution optical temperature measurements’, J. Cryst. Growth, 1998, 191, 252–260. doi: 10.1016/S0022-0248(98)00114-6
20.
AegerterM., LeventisN. and M.M. K. eds.: ‘Aerogels handbook’, 2011, New York, Springer.
21.
RatkeL. and KorektG.: ‘Solidification of al-pb base alloys in low gravity’, Z. Metallkde., 2000, 91, 919–927.
22.
AlkemperJ., RatkeL. and SousS.: ‘Directional solidification of eutectic AlNi alloys in a new aerogel based furnace’ in ‘Proc. 4th decennial conference on solidification processing’, (eds. J. Beech and H. Jones), 463–467; 1997, Sheffield, Department of Engineering Materials.
23.
SteinbachS. and RatkeL.: ‘ARTEX — In situ observation of directional solidification of binary aluminium alloys on TEXUS’, Microgravity Sci. Technol., 2005, 16, 111–115. doi: 10.1007/BF02945959
24.
TscheuschnerD. and RatkeL.: ‘Investment casting in silica aerogels’, Mat. Sci. Forum, 2000, 329–330, 479–486. doi: 10.4028/www.scientific.net/MSF.329-330.479
25.
RatkeL., SteinbachS., MüllerG., HainkeM., FriedrichJ., RooszA., FautrelleY., DupuoyM. D., ZimmermannG., WeissA., LacazeJ., ValdesR., GrünG.-U., NicolaiH.-P. and Gerke-CantowH.: ‘MICAST — The effect of magnetically controlled fluid flow on microstructure evolution in cast technical Al-alloys’, Microgravity Sci. Technol., 2005, 16, 99–103. doi: 10.1007/BF02945956
