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

The presence of additional elements in a multi-component Al–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.