Paper number 881

MECHANICAL BEHAVIOR OF AN ALUMINA FIBER REINFORCED ALUMINUM WIRE IN TENSION AND AFTER AXIAL TORSION

L.Weber¹, P. Canalis-Nieto¹, and A. Mortensen¹

1Laboratoire de la Métallurgie Mécanique, Swiss Federal Institute of Technology in Lausanne, CH-1015 Lausanne, Switzerland

Summary

The tensile behavior with and without preceding torsion of an aluminum/ 45vol% Nextel(r) 610 alumina fiber composite is investigated. For the undeformed wire the fracture strength varies between 1280 and 1400 MPa. From cyclic tension-tension tests a yield strength of the aluminum matrix of 25±5 MPa is calculated. Residual stresses in the matrix are in general tensile, ranging with some variability from 0 to 10 MPa. Twisting the wire results in a shortening of the wire and in a decrease in its fracture strength. Twisting and subsequent untwisting back to the initial configuration removes the shortening and causes no significant change in the wire fracture strength. The shortening and the decrease in fracture strength of the pre-twisted material is reasonably well predicted by analysis incorporating the influence of internal stresses caused by the twisting operation.

Keywords

metal matrix composites, alumina fibre, aluminum, tensile strength, yield, unloading, wire, torsion, Swift effect.