Relationship of the structure of structural aluminum alloys with characteristics of high-cycle fatigue in loading with ultrasonic frequency at room and low temperatures

1987 ◽  
Vol 19 (5) ◽  
pp. 620-625
Author(s):  
J. Fila
Keyword(s):  
Aluminum Alloys ◽  
Low Temperatures ◽  
High Cycle Fatigue ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Relationship Of

High Cycle Fatigue of Cast Aluminum Alloys at Ultrasonic Frequency

2006 ◽  
Author(s):  
C.C. Engler-Pinto ◽  
R.J. Frisch ◽  
J.V. Lasecki ◽  
J.E. Allison ◽  
X. Zhu ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
High Cycle Fatigue ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Cast Aluminum ◽  
Cast Aluminum Alloys

scholarly journals Usability of Ultrasonic Frequency Testing for Rapid Generation of High and Very High Cycle Fatigue Data

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2245
Author(s):  
Michael Fitzka ◽  
Bernd M. Schönbauer ◽  
Robert K. Rhein ◽  
Niloofar Sanaei ◽  
Shahab Zekriardehani ◽  
...  
Keyword(s):  
Strain Rate ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Reinforced Polymer ◽  
Very High Cycle Fatigue ◽  
Ultrasonic Fatigue ◽  
Fibre Reinforced Polymer ◽  
Very High

Ultrasonic fatigue testing is an increasingly used method to study the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) properties of materials. Specimens are cycled at an ultrasonic frequency, which leads to a drastic reduction of testing times. This work focused on summarising the current understanding, based on literature data and original work, whether and how fatigue properties measured with ultrasonic and conventional equipment are comparable. Aluminium alloys are not strain-rate sensitive. A weaker influence of air humidity at ultrasonic frequencies may lead to prolonged lifetimes in some alloys, and tests in high humidity or distilled water can better approximate environmental conditions at low frequencies. High-strength steels are insensitive to the cycling frequency. Strain rate sensitivity of ferrite causes prolonged lifetimes in those steels that show crack initiation in the ferritic phase. Austenitic stainless steels are less prone to frequency effects. Fatigue properties of titanium alloys and nickel alloys are insensitive to testing frequency. Limited data for magnesium alloys and graphite suggest no frequency influence. Ultrasonic fatigue tests of a glass fibre-reinforced polymer delivered comparable lifetimes to servo-hydraulic tests, suggesting that high-frequency testing is, in principle, applicable to fibre-reinforced polymer composites. The use of equipment with closed-loop control of vibration amplitude and resonance frequency is strongly advised since this guarantees high accuracy and reproducibility of ultrasonic tests. Pulsed loading and appropriate cooling serve to avoid specimen heating.

Effects of HIPping on high-cycle fatigue properties of investment cast A356 aluminum alloys

2003 ◽  
Vol 340 (1-2) ◽  
pp. 123-129 ◽  
Author(s):  
Min Ha Lee ◽  
Jae Joong Kim ◽  
Kyung Hoon Kim ◽  
Nack J. Kim ◽  
Sunghak Lee ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Investment Cast ◽  
A356 Aluminum

Experimental Characterization of Competition of Surface and Internal Damage in Very High Cycle Fatigue Regime

2017 ◽  
Vol 754 ◽  
pp. 79-82
Author(s):  
Wei Chang Zhang ◽  
Ming Liang Zhu ◽  
Fu Zhen Xuan
Keyword(s):  
Crack Growth ◽  
Slip Band ◽  
High Cycle Fatigue ◽  
Surface Measurement ◽  
Ultrasonic Frequency ◽  
Rotor Steel ◽  
Cycle Fatigue ◽  
Internal Damage ◽  
Very High Cycle Fatigue ◽  
Very High

Axially push-pull cyclic tests of a low strength rotor steel were performed up to the very high cycle fatigue regime at ambient environment under ultrasonic frequency. Fatigue tests were interrupted at selected number of cycles for surface morphology observation and roughness measurement with the help of a 3D surface measurement system (Alicona InfiniteFocusSL). The fatigue extrusions and slip band developed on the specimen surface were recorded. The influence of stress level on the number and morphology of slip band was discussed. The surface roughness of fatigue specimens was found to be increased with the increasing of fatigue cycles. The fatigued specimens were finally cracked from surface or interior micro-defects after observation of fracture surface by scanning electron microscopy. The internal damage behavior consists of crack initiation and early propagation from micro-defect, crack growth within the fish eye, and fast crack growth. It is observed that there exists a competition between surface and internal fatigue damage in the very high cycle fatigue regime, i.e., surface damage is gradually developed with the increasing of fatigue cycles, while the critical interior micro-defect can be dominant for fatigue cracking.

scholarly journals Investigations on the Fatigue Crack Propagation Threshold in Very High Cycle Fatigue

2014 ◽  
Vol 891-892 ◽  
pp. 357-362 ◽  
Author(s):  
Chong Wang ◽  
Danièle Wagner ◽  
Claude Bathias
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
High Cycle Fatigue ◽  
Fatigue Threshold ◽  
Fatigue Crack Propagation Rate ◽  
Ultrasonic Frequency ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Very High

Pariss law of fatigue crack propagation rate is well applied in the defect-tolerance fatigue approach. When carry out same approach in the very high cycle fatigue domain, the understanding of mechanism about fatigue crack propagation threshold which is obviously important, is helped. In the present work here, the fatigue crack propagation threshold of a surface crack for an Armco iron loaded in the VHCF regime was investigated by a new approach which combines the fracture surface analysis and the temperature recording on the surface during the test by an infra-red camera. The experiments were carried out on a sheet specimen under a 20 kHz ultrasonic frequency loading with IR images registration. Three stages of fatigue crack were identified with different mechanisms. It is found that the transition between initiation and crack propagation corresponds to the intrinsic fatigue threshold. It takes more than 99% of the gigacycle fatigue life to achieve this transition size.

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