Beobachtung des Schädigungsverhaltens von Aluminiumkolben unter TMF- und überlagerter TMF/HCF-Belastung

Monitoring of the damage behaviour of aluminium pistons under TMF- and combined TMF/HCF-load Because of the low density, the high thermal conductivity and the good strength, aluminium-silicium-casting alloys have prevailed as material for pistons since a few years. In order to dimension pistons for new downsizing-diesel engines, more precise simulations and further developed component tests are necessary to determine the fatigue strength. A particular challenge here is the realistic reproduction of the complex engine loads on test benches. By means of a specially developed test bench, it was nevertheless possible to stress piston samples with realistic thermal and mechanical loads and thus investigate their damage behaviour. In order to represent the damage so realistic and fast as possible, some appropriate operating parameters of the test bench had to be defined previously. Particular attention was paid for the selection of the piston cooling system, as this affected the temperature distribution in the piston and thus also the thermal load significantly. With the determined operating parameters, it was possible to carry out tests for the realistic reproduction of damage behaviour of aluminium pistons