Submicron Ti filaments strengthen AI composite
Submicron Ti filaments strengthen AI composite
Keywords Aluminium,Composite materials, Iowa State University, Titanium
A titanium-reinforced aluminium matrix composite that is said to be lighter and stiffer than other alloys, while retaining flexibility and strength, has been developed by researchers at Iowa State University, Ames, Iowa. One composite, formed into a 5cm (2in.) diameter cable, reportedly could support 250 metric tons (275 tons)of weight.
The material has a microstructure consisting of submicron thickness titanium filaments parallel to the rod axis in an aluminium matrix. The aluminium is made from high-purity,gas-atomized, rapidly solidified powder produced by the Ames Laboratory of the US Department of Energy. Characteristics of a 20 per cent Ti/80 per cent Al composite include: density of 3 g/cm3 (0.1lb/in.3);ultimate tensile strength of 600MPa (87ksi); ductility of 16 per cent reduction in area; and electrical resistivity of 43 nano-ohm-metres. The ratio of ultimate tensile strength to resistivity is 13.9MPa/nano-ohm-metre, compared with 12.6MPa/nano-ohm-metre for aluminium alloy 7049 in the T73 condition, the best commercial alloy available.
Possible applications include power generation tethers for orbiting spacecraft, and other applications requiring a combination of high strength, good ductility, and high electrical conductivity.
Further details are available from Alan Russell, Department of Materials Science and Engineering,301 Marston Hall, Iowa State University, Ames, Iowa 50011, USA. Tel: +1 515/294 3204.
