Influences of alloying elements Cu

Mn and Ni on the microstructure and mechanical properties of ZL109 piston alloy were investigated. The results show that Cu can promote the precipitation of stripped Al3CuNi and skeleton like Al7Cu4Ni phases

which are responsible for gradually increase of tensile strength of alloy at room temperature and 300 ℃. Ni can also promote the precipitation of Al3CuNi and Al7Cu4Ni phases

however

the change of mechanical properties at room and high temperature can be ignored. With the Mn content of 0.15%

the tensile strength at room and high temperature reaches peak value. With increasing Mn to 0. 30%

the tensile strength is decreased

which may be relate with the morphology of Mn-containing phase and its high temperature stability. It can be considered that the optimization compositions are 1. 0% Cu

0. 7% Ni

and 0. 15%Mn in ZL109 piston alloy.