The 5 years program aiming the application of rapidly solidified aluminum alloys (RSA) to Otto engine pistons is reviwed, with a focus on alloy process/properties improvement and production scale alloy evaluation. The conditions for alloy/process selection are discussed based not only on the mechanical properties evaluation, but on the material availability and piston forgeability.
Some engine test results based on the pilot production RSA are presented.
The main conclusion is that, although having room for further allay/process developments, the spray deposition process presents the best compromise for producing RSA for high performance Otto engine pistons. The alloy achieved a production step where it is possible to quantify the piston performance benefits.