ABSTRACT
In 1995, Federal-Mogul initiated a collaborative research programme with the Universities of Loughborough and Cambridge to model the development of microstructure in a range of Al–Si piston alloys. Commercial software packages are available which determine the chemical equilibrium in a system by employing numerical routines which minimize the total Gibbs free energy with respect to the amount and composition of the phases present in an alloy of specified composition as a function of temperature and pressure. In general, the role of intermetallics in near-eutectic Al–Si alloys in fatigue crack initiation and growth has been identified, but there has been little direct quantification of the effects of intermetallic spatial distribution, volume fraction, and local clustering on fatigue initiation, crack growth and coalescence. Quantitative statistical measures of the microstructural features and local environments giving rise to crack initiation and controlling crack propagation are expected to enhance our understanding of these multi-component Al–Si alloys.
