Mechanical properties of intermetallic phases in multi-component Al-Si alloys using nanoindentation

The presence of additional elements in a multi-component AI-Si alloy system allows many complex intermetallic phases to form. The mechanical properties of different intermetallic phases have been investigated using nanoindentation. In particular, the hardness and modulus of a number of phases have been established for a range of alloy compositions. The results show that both hardness and reduced modulus increase as the Ni ratio of the Al-Cu-Ni phases increases. The elastic modulus can be correlated with the formation temperature of the intermetallic phases. The intermetallic phases with a high heat of formation have a strong binding between atoms and therefore, their elastic modulus is also higher. (C) 2009 Elsevier Ltd. All rights reserved.