Ti-6Al-3Nb-2Zr-1Mo合金室温压缩蠕变行为及位错类型研究

Study on Compressive Creep Behavior at Room Temperature and Dislocation Type of Ti-6Al-3Nb-2Zr-1Mo Alloy

  • 摘要: 研究Ti-6Al-3Nb-2Zr-1Mo合金在不同外加应力下的室温压缩蠕变行为,拟合了蠕变曲线,计算出蠕变发生第二阶段的临界值,并对不同应力水平压缩后的合金显微组织进行TEM观察,研究其位错滑移类型。结果表明:室温条件下,Ti-6Al-3Nb-2Zr-1Mo合金压缩蠕变-时间曲线符合时间强化指数模型,该合金发生蠕变第二阶段的临界值为518 MPa,这为深海装备的安全设计提供了依据。Ti-6Al-3Nb-2Zr-1Mo合金室温压缩蠕变机制主要是位错滑移,其中基面滑移最容易启动,其次是柱面滑移和锥面滑移。结合微观组织分析与蠕变曲线可以判断锥面滑移对蠕变有较大贡献。

     

    Abstract: Compressive creep behavior and mechanism at room temperature of Ti-6 Al-3 Nb-2 Zr-1 Mo alloy under different applied stresses were investigated, the creep curves were fitted, the critical value of the second stage of creep calculated, the microstructures of the alloy after compression at different stress levels observed by TEM, and the dislocation slip types studied. The results showed that the compressive creep curve of Ti-6 Al-3 Nb-2 Zr-1 Mo titanium alloy conformed to the time-strengthening model at room temperature, and the critical value of the second stage of creep was 518 MPa, which laid a foundation for the safety design of deep-sea equipment. The creep mechanism of Ti-6 Al-3 Nb-2 Zr-1 Mo titanium alloy at room temperature was mainly dislocation slip, and the slip system with the most easy starting was basal slip, followed by prismatic slip and pyramidal slip. By microstructure and creep curve analysis, it was concluded that pyramidal slip had a great contribution to creep deformation.

     

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