Effects of Dwell Time on the Deformation and Fatigue Behaviour of A356-T7 Cast Aluminium Alloys Used in High Specific Power IC Engine Cylinder Heads
Journal article, 2020

The electrification of automotive powertrains in recent years has been driving the development of internal combustion engines towards reduced volumes with higher power outputs. These changes place extreme demands on engine materials. Engineers employ the computer-aided engineering approach to design reliable and cost-effective engines. However, this approach relies on accurate knowledge of the material deformation and fatigue characteristics during service-like loading. The present study seeks to investigate the effect of dwell times on the deformation and fatigue behaviour of the A356-T7 + 0.5 wt.% Cu alloy used to cast cylinder heads. In particular, we study the effect of dwell time duration at various temperatures. A combined fatigue-dwell testing procedure, with the dwell at the maximum compressive strain, replicates the service conditions. It is found that the material exhibits a stress relaxation behaviour with a decreasing relaxation rate. At lower temperatures, the load level influences the relaxation more than at elevated temperatures. However, the dwell does not significantly affect the hardening behaviour or the life of the tested alloy. Finally, we model the time-dependent material behaviour numerically. The Chaboche model, combined with a Cowper–Symonds power-law, is found to capture the visco-plastic deformation behaviour accurately.

fatigue

cylinder head

mechanical properties

dwell

deformation behaviour

cast aluminium

Author

Elanghovan Natesan

Chalmers, Industrial and Materials Science, Engineering Materials

Knut Andreas Meyer

Chalmers, Industrial and Materials Science, Material and Computational Mechanics

Stefan Eriksson

Volvo Cars

Johan Ahlström

Chalmers, Industrial and Materials Science, Engineering Materials

Christer Persson

Chalmers, Industrial and Materials Science, Engineering Materials

Materials

1996-1944 (ISSN)

Vol. 13 12 2727

Development of analysis models for thermomechanical fatigue

Swedish Energy Agency, 2013-10-01 -- 2018-12-31.

Areas of Advance

Transport

Materials Science

Subject Categories

Applied Mechanics

Vehicle Engineering

Metallurgy and Metallic Materials

DOI

10.3390/ma13122727

More information

Latest update

8/19/2020