Ti-46Al-1Mo-0.2Si金属间化合物中的高温内耗及其与蠕变行为的比较
High temperature internal friction in a Ti-46Al-1Mo-0.2Si intermetallic, comparison with creep behaviour
AI总结：
本研究通过高温内耗谱分析Ti-46Al-1Mo-0.2Si合金两种微观组织，发现弛豫峰源于Ti原子扩散，激活能与蠕变结果一致，并揭示了蠕变抗力的差异。
摘要：
为获得超塑性变形所需的细晶微观组织，以便在后续加工中使用，已开发出含钼的先进γ-TiAl基金属间化合物。在本工作中，我们研究了Ti-46Al-1Mo-0.2Si（原子百分比）合金的两种不同微观组织状态：晶粒尺寸大于300微米的铸态材料，以及晶粒尺寸小于20微米的热挤压材料。我们使用了一台专门为高温内耗测量而开发的力学谱仪，来研究高温下发生的缺陷迁移过程。研究了不同频率下的内耗谱，并分析至1360 K，以表征该温度范围内出现的弛豫过程。一个弛豫峰，其最大值位于900 K至1080 K之间（取决于振荡频率），被归因于Al-VTi-Al弹性偶极子的应力感生再取向引起的Ti原子扩散。对铸态和挤压态两种微观组织状态下的高温背景进行了分析，测量了表观激活参数，特别是表观激活能分别为E铸态(内耗) = 4.4 ± 0.05 eV和E挤压态(内耗) = 4.75 ± 0.05 eV。将这些结果与通过蠕变变形在同一材料上获得的结果进行了比较。我们可以得出结论，通过内耗分析获得的激活参数与蠕变测量得到的参数一致。此外，高温背景的分析使得能够确定两种微观组织状态在蠕变抗力上的差异。
英文摘要：
Advanced g-TiAl based intermetallics Mo-bearing have been developed to obtain the fine-grained microstructure required for superplastic deformation to be used during further processing. In the present work we have studied an alloy of Ti-46Al-1Mo-0.2Si (at%) with two different microstructures, as-cast material with a coarse grain size above 300 mm, and the hot extruded material exhibiting a grain size smaller than 20 mm. We have used a mechanical spectrometer especially developed for high temperature internal friction measurements to study the defect mobility processes taking place at high temperature. The internal friction spectra at different frequencies has been studied and analyzed up to 1360 K in order to characterize the relaxation processes appearing in this temperature range. A relaxation peak, with a maximum in between 900 K and 1080 K, depending on the oscillating frequency, has been attributed to Ti-atoms diffusion by the stress-induced reorientation of Al-VTi-Al elastic dipoles. The high temperature background in both microstructural states, as-cast and extruded, has been analyzed, measuring the apparent activation parameters, in particular the apparent energies of Ecast(IF) 4.4 +- 0.05 eV and Eext(IF) 4.75 +- 0.05 eV respectively. These results have been compared to those obtained on the same materials by creep deformation. We may conclude that the activation parameters obtained by internal friction analysis, are consistent with the ones measured by creep. Furthermore, the analysis of the high temperature background allows establish the difference on creep resistance for both microstructural states
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
