The variation of beta phase morphology after creep and negative creep for duplex titanium alloys
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The creep resistance of SP700 (Ti–4.5Al–3V–2Mo–2Fe) is superior to Ti–6–4 (Ti–6Al–4V) at 500 °C under a constant load corresponding to an initial stress of 100 MPa. The β phase grains in the SP700 alloy prefer to orient along the loading axis in contrast to the Ti–6–4 alloy. The grain growth occurs during the stress drop incubation period. The observation of different amounts of negative creep/anelasticity upon loading is closely associated with the difference in the amount of grain/subgrain coarsening.
KeywordsTitanium Alloy Internal Stress Creep Rate Creep Strain Stress Drop
This work was carried out with financial support from the National Science Council of the ROC, Taiwan, under the grants of NSC-94-2216-E-019-017 and NSC-95-2221-E-019-019. The authors gratefully acknowledge this support.
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