EFFECT OF TEMPERATURE ON FATIGUE CRACK BEHAVIOUR IN DIFFERENT ALLOYS

F. S. Silva        

Anales de la Mecánica de la Fractura, nº 20 . 2003 . Pág. 231 -236
Ver (.pdf): GEF029

Resumen: This paper deals with the role of temperature in the behaviour of fatigue cracks in different alloys used in the aircraft industry. Three different alloys were studied: an aluminium alloy (Al 7175), a titanium alloy (Ti6Al4V), and an high strength steel (34CrNiMo6). Push-Pull tests (R = -1) were carried out at different temperatures, from low temperatures, (-100ºC), to somehow high temperatures (+ 400ºC), in air. At each temperature the shape of the da/dN-Kmax curve was assessed, as well as the initiation life, (a – Nf curve). The relation initiation life/propagation life was also assessed, (a – N/Nf curve). The effect of temperature in the referred subjects was discussed. The existence of a ductile-brittle fatigue transition temperature, parallel to the monotonic ductile-brittle transition temperature, although these transition temperatures are not the same, was assessed. Even on materials without a monotonic ductile-brittle transition temperature, a ductile-brittle fatigue transition temperature was detected.

LocalizaciónBenicassim

Mechanical Engineering Department, Minho University. Guimarães - Portugal