Materials and Processing Methods to Improve the Properties of Aluminium Alloy Cylinder Heads

摘要

Conventional gravity die-casting methods have not been able to realise the full, significant potential of high-strength, temperature-resistant aluminium foundry alloys. On the other hand, evolutionary process improvements are now asymptotically approaching what is technically possible even when taking into account the most recent metallurgical knowledge and optimisation of composition of these alloys. A paradigm change is unavoidable.Already now, dynamic casting methods produce much improved static and fatigue strength values even if solidification takes place only under atmospheric pressure. The proposed approach offers the possibility for mass production of even the most complex components such as cylinder heads in high-strength, temperature-resistant aluminium alloys which are generally classed as difficult or almost impossible to cast. The proposed method, which involves application of increased ambient pressure during the filling of the mould and solidification of the metal, is both viable and reliable for large series production.