Anelastic Damping of Resonant Ultrasound Spectroscopy (RUS) in Ni-rich Solid Solution Alloys at Very High Temperatures

元素铼（Re）是镍基高温合金在高温下优异力学性能的主要原因。作为涡轮部件的材料，这些合金也暴露在振动中。共振超声光谱（RUS）可以用来精确地确定方向相关的弹性常数，直到阻尼发生。根据合金的不同，在1000°C左右，远低于~1350°C的固相温度，会产生明显的阻尼。目前对该温度和频率范围内的成分相关阻尼特性知之甚少。在金属和合金的椅子上，一个自制的RUS装置已经投入使用，可以测量高达1500°C的温度。初步研究表明，稀土等固溶体增强剂会影响富镍固溶体在高温下的阻尼性能。高比例的重合金元素显著降低了材料的激活能和阻尼起始温度。有证据表明，观察到的阻尼是由于缺陷沿交变应变场传输。在拟议的项目中，将生成数据来支持这一假设。下面是三个主要问题。1)如何在宽温度范围内精确量化50 - 500khz频率范围内的共振超声光谱中的阻尼？2)稀土、钌等难熔合金元素如何定量影响富镍固溶体基体的温度依赖性阻尼性能？3)从这些观测结果中可以确定预测温度相关机械阻尼的规则是什么？为了回答这些问题，必须对实验设置进行优化，使测量的基础阻尼最小，并对共振峰进行自动评估。工艺路线对阻尼性能的影响将通过进一步的研究来量化，以确定进一步研究的标准。采用单相试样确定合金元素Re和Cr对RUS阻尼的影响。通过对含Re和Cr合金试样阻尼性能的定量测量，推导出具有优化阻尼性能的合金的设计规律。

The element rhenium (Re) is largely responsible for the outstanding mechanical properties of nickel-base superalloys at high temperatures. As a material for turbine components, these alloys are also exposed to vibration. The resonance ultrasonic spectroscopy (RUS) can be used to precisely determine the orientation-dependent elastic constants until damping occurs. Significant damping sets in, depending on the alloy, at about 1000°C, well below the solidus temperature of ~1350°C. There is currently little knowledge about the composition-dependent damping properties in this temperature and frequency range. At the Chair of Metals and Alloys, a self-made RUS apparatus has been put into operation, with which measurements up to 1500°C are possible. Preliminary work shows that solid solution strengtheners such as Re influence the damping properties of Ni-rich solid solutions at very high temperatures. A high proportion of heavy alloying elements significantly lowers the activation energy and onset temperature of damping. There is evidence that the observed damping is due to defect transport along the alternating strain field. In the proposed project, data will be generated to support this hypothesis. The following three main questions arise. 1) How can damping in resonance ultrasonic spectroscopy in the frequency range 50 - 500 kHz be quantified precisely and reproducibly over a wide temperature range? 2) How do refractory alloying elements such as Re and Ru affect the temperature-dependent damping properties of the Ni-rich solid solution matrix quantitatively? 3) What rules for predicting the temperature-dependent mechanical damping can be determined from these observations? To answer these questions, the experimental setup must be optimized with respect to a minimum base damping of measurement and to the automated evaluation of the resonance peaks. The influence of the process route on the damping properties is to be quantified by further investigations to define standards for the further investigations. The influence of the alloying elements Re and Cr on RUS damping will be determined using single-phase samples. From the quantitative measurements of the damping properties of the samples containing Re and Cr, a model will be derived from which rules for the the design of alloys with optimized damping behavior can be derived.