TiAl Charger

TiAlCharger - Titanium Aluminide Turbochargers

Improved Fuel Economy, Reduced Emissions

Project objectives

• development of production processes for turbo charger wheel shaft assemblies made of titanium aluminide alloys
• rotational speeds up to 220.000 rpm
• weight savings of 60 % compared to nickel super alloys 
• operation at exhaust gas temperatures up to 950°C
• reduction of mass moment of inertia of 36% compared to nickel super alloys
• increased fuel to air ratios thereby improving of vehicle efficiency by 5%
• reduction of CO2 emissions by 8%.

The technologies behind our innovations are electron beam melting (eb melting) and electron beam brazing (eb brazing). The eb melting process has the potential to fabricate a turbine charger wheel from successive layers of powder allowing a hollow, lightweight, low-inertia rotor-wheel to be formed. The TiAl wheel will be joined to the steel shaft using the EB brazing process, the challenge being to create a joint between dissimilar materials that is robust enough to withstand vibrations, high temperatures and rotational speeds present in a turbocharger unit. This fabrication methods provide the possibility to manufacture turbocharger wheels from TiAl, which (if of the required quality) retain its strength at high temperatures, expanding the usage of turbochargers to a broad range of engine types. 

The research leading to these results has received funding from the European Union’s Seventh Framework Programme managed by REA – Research Executive Agency http://ec.europa.eu/rea (FP7/2007-2013) under grant agreement no FP7-SME-2012-315226.