Effect of rare earth Yb addition on mechanical properties of Al–5·3Cu–0·8Mg–0·6Ag alloy

Abstract

The precipitation hardening response, microstructure and mechanical properties of three Al–5·3Cu–0·8Mg–0·6Ag based alloys containing 0, 0·15 and 0·25 wt-%Yb were investigated using optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. It is shown that increasing Yb content from 0 to 0·25 wt-% increased the tensile strength at all test temperatures up to 300 °C. The high strength of the alloys with Yb is attributed to the high density and high thermal stability of fine Ω precipitates.