Abstract
Customers demand light-weight engines in addition to high power/torque and low fuel consumption. This is why aluminum alloys have been more often used for cylinder heads. Critical for the use of aluminum alloys for cylinder heads are strength and durability. Aluminum alloys, however, have complicated inelastic behavior under cyclic thermal condition, which prevents us from precise numerical analysis in estimating life. In our study, the mechanism of the low cycle fatigue and creep was clarified based on the mechanical properties of aluminum alloys, such as tensile, compressive, thermal fatigue and creep characteristics, which were determined by conducting tests on test pieces. The behavior of a cylinder head under cyclic thermal condition was reproduced by using a high-precision analysis method with cyclic creep taken into consideration.