Microstructure and properties of 2618-Ti heat resistant aluminum alloy

The mechanical properties of alloy 2618 with 0.5%(mass fraction) titanium and its microstructures in different states such as as cast and quenching aging were investigated. Titanium was added into the alloy with Al 5%Ti master alloy that was extruded severely. Al 3Ti particles in the microstructure of cast alloy 2618 Ti are very small because those of master alloy are also small. When titanium is used as an alloying element, it does not affect the morphology of Al 9FeNi phase in cast alloy, but decreases the grain size of as cast alloy remarkably. The grain size of quenching aging alloy 2618 decreases apparently due to the existence of a great deal of dispersive Al 3Ti particles. Adding 0.5%Ti has no effect on the room temperature tensile properties of alloy 2618, but apparently increases the elevated temperature instantaneous tensile properties and that of the alloy which is exposed at 250 ℃ for 100 h.