Light Turbocharger Compressor Wheels from Aluminium and Magnesium Investment Casting

Within the scope of a team work between Kühnle, Kopp & Kausch AG (KKK), Volkswagen AG, Sterling International Technologies Ltd. and the Fraunhofer Institute for Strength of Structures under Operational Conditions (LBF) compressor wheels of aluminium and magnesium investment casting were developed and investigated. Strength and fatigue tests, overspeed and field tests as well as metallographic checks were made in addition to the finite element calculations to optimize the stress under centrifugal forces in an appropriate way for the materials involved. The results and the knowledge gathered are to clarify whether magnesium alloys are an appropriate replacement for the proven standard aluminium alloy for turbochargers.