Handbook of case histories in failure analysis
Handbook of case histories in ... - Google Ksi??ki @ transportation components pp.17
provides and intersting example of excessive spline wear in Mirage III flown by RAAF - due to fretting wear. Very instructive pictures. Most probable cause:
incorrect machining error
does it look familiar to incorrect machining of the stub pipe?
Fretting wear is surface damage that occurs between two contacting surfaces experiencing cyclic motion (oscillatory tangential displacement) of small amplitude. At the contact areas, lubricant is squeezed out, resulting in metal-to-metal contact. Because the low amplitude motion does not permit the contact area to be relubricated, serious localized wear can occur. This type of wear further promotes two-body abrasion, adhesion and/or fretting fatigue (a form of surface fatigue) wear.
source and more info at :
Fretting Wear in Lubricated Systems - most important points:
- increasing load or unit pressures tend to generate higher wear rates
- Fretting seems to progress more rapidly in friction couples that have smooth surface finishes and close fits.