This causes conventional pistons made of aluminium to reach their limits. The new BINE Projektinfo brochure entitled "Steel pistons for more efficient diesel engines" (14/2016) presents a cooling concept for engine pistons using a liquid metal alloy. Compared with aluminium, steel offers greater strength against thermal and mechanical loads.
Innovative cooling concept enables more efficient engine
In diesel engines, particularly the piston head and the chemical stability of the engine oil are prone to temperature peaks. This can lead to cracks in the material and coking reactions by the oil. Therefore a coolant was needed which compensated for the poorer thermal conductivity of steel compared with aluminium. It also needs to remain stable at temperatures above 500 °C. The researchers therefore used a mixture of sodium and potassium as a cooling medium in a modified, serial-produced steel piston with a cooling channel. The fast heat dissipation enables an even temperature distribution in the piston. [...]
The full text of the press release can be found here.