Effect of stress ratio on fatigue crack growth behavior of magnesium alloys

Zainuddin Sajuri, Y. Miyashita, Y. Mutoh

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Fatigue crack growth (FCG) behavior of magnesium alloys at room temperature (20°C-55%RH) was investigated. Center cracked plate tension (CCT) specimens were used in the FCG tests for applying both tension-compression and tension-tension loading. The effects of R ratio and crack closure on fatigue crack growth behavior of extruded AZ61 and AZ91D magnesium alloys were investigated. From the results, it is found that stress ratio influences the threshold value ΔKth for the materials used. The threshold value decreased with increasing stress ratio. The relationship between fatigue crack growth rate da/dN and stress intensity factor range Δ K for AZ61 was almost identical to that for AZ91D. The effective stress intensity factor range ΔKeff values for R=-1, 0.1 and 0.5 were significantly low compared to Δ K values in the near-threshold region while the difference became smaller as the stress intensity factor range increased. This can be explained by the effect of crack closure, which is more pronounce in the near-threshold region. The effect of R ratio was diminished and all the growth curves laid on the same curve when the fatigue crack growth rate plotted as a function of ΔKeff.

Original languageEnglish
Pages (from-to)81-86
Number of pages6
JournalMaterials Science Forum
Volume419-422
Issue numberI
Publication statusPublished - 2003
Externally publishedYes

Fingerprint

stress ratio
magnesium alloys
Magnesium alloys
Fatigue crack propagation
cracks
stress intensity factors
Stress intensity factors
Crack closure
crack closure
thresholds
curves
closures
room temperature

Keywords

  • Crack closure
  • Effective Stress Intensity Factor
  • Fatigue Crack Growth
  • Magnesium Alloys
  • Stress Ratio

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Effect of stress ratio on fatigue crack growth behavior of magnesium alloys. / Sajuri, Zainuddin; Miyashita, Y.; Mutoh, Y.

In: Materials Science Forum, Vol. 419-422, No. I, 2003, p. 81-86.

Research output: Contribution to journalArticle

Sajuri, Zainuddin ; Miyashita, Y. ; Mutoh, Y. / Effect of stress ratio on fatigue crack growth behavior of magnesium alloys. In: Materials Science Forum. 2003 ; Vol. 419-422, No. I. pp. 81-86.
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