Case 1819 ยท Public preview
Vibration Loads Above Yield Can Drive Low-Cycle Fatigue in Cast Magnesium
Two mounting tabs on a cast-magnesium cover fractured during a multi-axis vibration test, with the exact failure time unknown.
Secondary-electron SEMBackscattered-electron SEMEDSFractographyCoating-strain-field examination
What the evidence preview establishes
The tabs most likely failed by low-cycle fatigue during vibration because local loads exceeded the yield strength of the cast magnesium. The fracture morphology and damage extending into the nearby coating supported repeated high-strain bending rather than a single brittle event.
Why this case matters
A vibration fracture can be governed by plastic strain even when the test input appears modest. Instrument the part near the suspected resonance and inspect both the fracture surface and surrounding coating, because an extended coating-strain field can reveal repeated bending beyond the nominally broken section.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.