Fatigue and fatigue crack growth of aluminium alloys at very high numbers of cycles

Very high cycle fatigue of copper: Evolution, morphology and locations of surface slip markings

“…The hardest materials were found to exhibit a gradual decrease of the fatigue resistance with increasing number of cycles, whereas the softest alloys were found to present a plateau from 10 7 up to 10 9 -10 10 cycles [2]. Titanium and tantalum [3] and aluminium [4] exhibit a decrease of the fatigue resistance at a constant rate from 10 4 up to 10 8 cycles. The S-N curve for pure copper displays two slopes: the decrease of the fatigue resistance is stronger from 10 4 up to 10 7 cycles than from 10 7 up to 10 9 cycles [5][6][7][8].…”

A model to predict S–N curves for surface and subsurface crack initiations in different environmental media

“…Nishijima and Kanazawa [15] attributed the reason why the fatigue life for internal failure is longer than that for surface failure to the fact that the stress intensity factor for flaws with the same size in the material interior is smaller than that at the surface. The influence of some factors, such as loading frequency [12,14,20,21], surface finishing condition [8,16,22], material microstructure state [23][24][25] and environmental media [10,11,26], on the VHCF properties of high strength steels has been widely studied. Among them, the effect of ultrasonic frequency on the estimated fatigue strength has been intensively studied in order to make sure that the fatigue results obtained by using ultrasonic testing and conventional fatigue equipment with a low frequency are comparable.…”

“…Among them, the effect of ultrasonic frequency on the estimated fatigue strength has been intensively studied in order to make sure that the fatigue results obtained by using ultrasonic testing and conventional fatigue equipment with a low frequency are comparable. Stanzl-Tschegg and Mayer [20] showed that the frequency influences might be divided into intrinsic and extrinsic. The former one is related to strain rate, dislocation structures, crack formation and propagation.…”

Application of full-surface view in situ thermography measurements during ultrasonic fatigue of cast steel G42CrMo4

“…It enables the economic and less time-consuming assessment of the melt cleanliness [14] due to the high testing frequency during fatigue testing [20,21,22,23,24,25,26]. In addition, this method enables the in situ investigation of the influence of nonmetallic inclusions on the crack initiation by various complementary non-destructive testing methods, i.e.…”