Anelasticity of Fe-based Ordered Solid Solutions and Intermetallics Compounds

本文将结合不同的力学谱技术，在较宽的频率、温度和振幅范围内，系统地研究短程和长程D 03和B2有序合金的内摩擦和滞弹性弛豫谱（Fe-Al、Fe-Si、Fe-Co、Fe-Cr，包括金属间化合物Fe 3Al、FeAl、Fe 3Si和FeCo），以及具有不同有序度的混合多组分组合物（例如：Fe-（Al+Cr）、Fe-（Si+Al））。目标有两个：（1）在基本面上，滞弹性的机制是从间隙、空位和位错亚结构来阐明的。这包括新的信息，间隙周围的替代原子的分布与短程有序，流动性的空缺和扭结对位错，间隙原子和空缺之间的相互作用。(2)从应用的角度来看，这些特定的力学谱结果可用于研究Fe 3Al和Fe 3Si基金属间化合物的屈服应力异常（位错移动性和钉扎机制）、各种类型的脆性以及Fe-Al、Fe-Cr和Fe-Co基合金的高阻尼能力（振动和噪音降低）等商业上重要的现象。

Different mechanical spectroscopy techniques will be combined to study systematically, over wide ranges of frequency, temperature, and amplitudes, the spectra of intemal friction and anelastic relaxation in short and long range D03 and B2 ordered alloys (Fe-Al, Fe-Si, Fe-Co, Fe-Cr, including the intermetallic compounds Fe3Al, FeAl, Fe3Si, and FeCo), and mixed multi-component compositions with different degree of order (e.g.: Fe-(Al+Cr), Fe-(Si+Al)). The goals are twofold: (1) On the fundamental side, the mechanisms of anelasticity are to be clarified in terms of interstitial, vacancy and dislocation substructures. This includes new information about the distribution of interstitial around substitutional atoms with short range ordering, mobility of vacancies and kink pairs on dislocations, and interaction between interstitial atoms and vacancies. (2) Under the viewpoint of the application, such specific mechanical spectroscopy results are used to study commercially important phenomena, like yield stress anomalies of Fe3Al and Fe3Si-based intermetallics (dislocation mobility and pinning mechanisms), various types of brittleness, and high damping capacity of Fe-Al, Fe-Cr and Fe-Co based alloys (vibration and noise reduction).