Mechanical characterization of aluminium alloys for high temperature applications Part1: Al-Si-Cu alloys

Abstract

New challenges for the Aluminium alloys
used for the production of castings for
automotive engine components are coming
from the evolution trend of Internal
combustion engines towards higher specific
power output. Cylinder heads, in particular,
have to withstand higher operating
temperatures and stress levels. The present
study is aimed to evaluate the mechanical
properties at high temperature of Al-Si-Cu
aluminium alloys traditionally used for the
production of cylinder head castings. The
obtained results are very promising,
especially for what concerns the modified
alloys. In fact, the resistance of base Al-Si-Cu
alloy is fairly good up to 150°C, but drops at
250°C, while some interesting improvements
have been achieved by modifying the
composition of the base alloy with the
addition of Mn and Ni, resulting in an
increase of strength and ductility at both room
and high temperatures. Further studies related
to High Cycle Fatigue and creep resistance at
high temperature are under way. Moreover,
the research will be continued also
considering other alloys families, like Al-Mg
and Al-Cu and the results will be discussed in
a second part of the article.
RI