2 INDEPENDENT STRAIN-HARDENING MECHANISMS IN SINGLE-CRYSTAL GAMMA-TI-56AL COMPOUND

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:192

Article; Proceedings Paper

关键词: STRAIN;    HARDENING;    CRYSTALS;    TITANIUM;    ALUMINUM;   

DOI  :  10.1016/0921-5093(94)03248-3

来源: Elsevier

【 摘 要 】

The strain hardening of gamma-Ti-56Al by superdislocations (b=[101]) occurs by two independent mechanisms in two different temperature ranges: from room temperature to approximately 623 K; and from 623 to 1073 K. The activation energy for the low temperature mechanism was found to be 0.014 eV, compared to 0.2-0.22 eV for the high temperature mechanism. The transition from the low temperature mechanism to the high temperature mechanism occurs near 623 K where a burst of double jogs is believed to occur through a thermally activated process. Many extended double jogs 15-20 nm wide were observed in the alloy deformed at 673 K. The beginning of the extended jog formation near 673 K in Ti-56Al is coincident with the near-zero value of the strain rate sensitivity parameter near 673 K in Ti-54Al.

【 授权许可】

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