Temperature dependence of impact toughness in Al–Li–Cu–Mg–Zr alloys

Abstract

The dependence on temperature of the impact toughness in Al–Li–Cu–Mg–Zr alloys was investigated focusing on the low temperature impact toughness. The impact toughness of Al–Li–Cu–Mg–Zr alloys in the low temperature region (≤ 423 K) increased with decreasing temperature. Laminated cracks, the number of which increased with the increase in impact toughness in the low temperature region, were observed and it was suggested that the appearance of these cracks resulted in part of the increase of the impact toughness of this alloy. The spectra of potassium and sodium were detected from the fracture surface of a specimen tested at room temperature. This indicates that a low melting point metal phase seems to affect the impact toughness near room temperature, i.e. this phase seems to produce the liquid metal embrittlement locally at the grain boundary.MST/787