Recent developments in ultrasonic fatigue

• Published in: Fatigue & fracture of engineering materials & structures Vol. 39; no. 1; pp. 3 - 29
• Main Author: Mayer, H.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.01.2016; Wiley Subscription Services, Inc
• Subjects: Alloys; Fatigue failure; Fatigue strength; Fatigue testing; High cycle fatigue; high frequency; High strength steels; Metal fatigue; Plastic deformation; ultrasonic fatigue; Ultrasonic technology; Ultrasonic testing; Ultrasonic tests; very high cycle fatigue
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/ffe.12365

The recently increased interest in very high cycle fatigue properties of materials has led to extended use and further development of the ultrasonic fatigue testing technique. Specimens are stimulated to resonance vibrations at ultrasonic frequency, where the high frequency allows collecting lifetime data of up to 1010 cycles and measuring crack propagation rates down to 10−12 m per cycle within reasonable testing times. New capabilities and methods of ultrasonic testing and outstanding results obtained since the year 1999 are reviewed. Ultrasonic tests at load ratios other than R = −1, variable amplitude tests, cyclic torsion tests and methods for in situ observation of fatigue damage are described. Advances in testing at very high temperatures or in corrosive environments and experiments with other than bulk metallic materials are summarized. Fundamental studies with copper and duplex steel became possible and allowed new insights into the process of very high cycle fatigue damage. Higher cyclic strength of mild steels measured at ultrasonic frequency because of plastic strain rate effects are described. High‐strength steels and high‐alloy steels are less prone to frequency influences. Environmental effects that can lead to prolonged lifetimes in some aluminium alloys and possible frequency effects in titanium and nickel and their alloys are reviewed.