EFFECT OF MICROSTRUCTURE CHARACTERISTICS ON THE FATIGUE AND CRACK PROPAGATION BEHAVIOR OF THE ALUMINUM CAST ALLOY EN AC-ALSI7MG0.3

摘要

Fatigue, crack propagation and fracture behavior of aluminum cast alloy EN AC-AlSi7Mg0.3 dependent on the microstructure characteristics were investigated. For this purpose, samples were cast and selected ones were hot isostatically pressed (HIPed) to remove the residual porosity. To investigate the effect of Si eutectic morphology, solution annealing temperatures and holding times were adjusted. During fatigue test, the number of cycles to crack initiation and the corresponding location of crack initiation were determined by means of thermographic, resistometric and fractographic investigations. Porosity and Si eutectic morphology were correlated to fatigue and crack propagation behavior.