Fatigue Strength Effect of Thread Forming Process in Cast Aluminum 2006-01-0780
Two thread forming processes, rolling and cutting, were studied for their effects on fatigue in cast aluminum 319-T7. Material was excised from cylinder blocks and tested in rotating-bending fatigue in the form of unnotched and notched specimens. The notched specimens were prepared by either rolling or cutting to replicate threads in production-intent parts. Cut threads exhibited conventional notch behavior for notch sensitive materials. In contrast, plastic deformation induced by rolling created residual compressive stresses in the notch root and significantly improved fatigue strength to the point that most of the rolled specimens broke outside the notch. Fractographic and metallographic investigation showed that cracks at the root of rolled notches were deflected upon initiation. This lengthened their incubation period, which effectively increased fatigue resistance.
Citation: Blaha, J., Langmayr, F., Schackert, S., Chang, C. et al., "Fatigue Strength Effect of Thread Forming Process in Cast Aluminum," SAE Technical Paper 2006-01-0780, 2006, https://doi.org/10.4271/2006-01-0780. Download Citation
Author(s):
Johann Blaha, Franz Langmayr, Soeren Schackert, Cherng-Chi Chang, Diwakar Krishnaiah, Paul N. Crepeau
Affiliated:
AVL LIST GmbH, General Motors Corporation
Pages: 7
Event:
SAE 2006 World Congress & Exhibition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Fatigue Research & Applications, 2006-SP-2031
Related Topics:
Forming
Fibers
Fatigue
Cutting
Engine cylinders
Aluminum
Drag
Casting
Plastics
Roll
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