Nextel (TM) 610 alumina fibre reinforced aluminium: influence of matrix and process on flow stress

Continuous alumina fibre reinforced aluminium matrix composites are produce d using two different liquid metal infiltration methods, namely direct sque eze casting and gas pressure infiltration. Net-shape fibre performs for lon gitudinal parallel tensile bars are prepared by winding the Nextel (TM) 610 alumina fibre (3M, St Paul, MN) into graphite moulds. High purity aluminiu m, two binary (Al-6% Zn and Al-1% Mg) and one ternary (Al-6% Zn-0.5% Mg) al uminium alloys are used as matrix materials. The composite is tested in uni axial tension-compression, using unload-reload loops to monitor the evoluti on of Young's modulus. A linear dependence between Young's modulus and stra in is observed; this is attributed, by deduction, to intrinsic elastic non- linearity of the alumina fibre. This conclusion is then used to compare on the basis of the in situ matrix flow curve the influence of matrix composit ion and infiltration process on the composite stress-strain behaviour. (C) 2001 Elsevier Science Ltd. All rights reserved.