Alloy Selection

Aluminum is the metal of choice for weight savings in the cylinder block, but the performance requirements and manufacturability issues will drive the choice of a specific aluminum alloy.

There are a range of different alloys that are commonly used for aluminum castings.
The engine designer has to select the aluminum alloy that offers the best combination of mechanical properties, castability, and machinability.

Aluminum being poured into the mold

Here are three aluminum alloys which can be considered for this application --

*242 aluminum alloy with a T77 heat treat*	*319 aluminum alloy with a T5 heat treat*	*A356 aluminum alloy with a T6 heat treat*
NOTE -- While published alloy properties may state levels of mechanical performance, actual performance can vary due to section size, porosity and gating design in the casting. -- Thick section sizes (vs. thin section sizes) cool slower generating somewhat lower properties. -- Porosity is a function of hydrogen content, oxides and metal composition. Higher porosity levels give lower properties. -- The gating needs to optimize directional solidification and maintain head pressure through the solidification of the metal.

Back