J. Phys. Colloques
Volume 48, Numéro C3, Septembre 19874th International Aluminium Lithium Conference
|Page(s)||C3-123 - C3-128|
J. Phys. Colloques 48 (1987) C3-123-C3-128
MECHANICAL PROPERTIES AND MICROSTRUCTURE OF Al-Li INVESTMENT CASTINGST.G. HAYNES III1, M. WYTE1 et D. WEBSTER2
1 Rex Precision Products Inc., P.O. Box 270, Gardena, CA 90247-0827, U.S.A.
2 20565 Verde Vista Lane, Saratoga, CA 95070, USA
The object of this program is to develop Al-Li investment castings with mechanical properties at least equivalent to A356 (0.2% tensile yield strength 260-310 mPa and tensilr elongation 3-5%) but with a 5-10% reduction in density. Thin wall castings with complex shapes have been successfully cast and 25 compositions have been examined with lithium contents up to 3.6%. Mechanical properties well above the minimum requirements for A356 have been obtained with some compositions. Densities as low as 2.44 g/ml were reached with the higher lithium alloys. The microstructure, fracture behaviour and effect of lithium on the mechanical properties of various alloy matrices is described. Future work will be aimed at increasing the strength of the alloys to the levels of A201.