Knowing material behavior is crucial for successful design, especially given the growing number of next-generation energy, defense, and manufacturing systems operating in extreme environments. Specific applications for materials in extreme environments include fusion energy, semiconductor manufacturing, metal additive manufacturing, and aerospace. With increased applications, awareness of foundational science for materials in extreme environments is imperative. The speed of sound provides insights into phase boundaries, like shock-induced melting. Thermodynamic integration of the speed of sound enables the deduction of other desirable properties that are difficult to measure accurately, like density, heat capacity, and expansivity. Metrology advancements enable the speed of sound to be measured at extreme conditions up to 15 000 K and 600 GPa. This comprehensive review presents state-of-the-art sound speed metrology while contextualizing it through a historical lens. Detailed discussions on new standards and metrology best practices, including uncertainty reporting, are included. Data availability for condensed matter speed of sound is presented, highlighting significant gaps in the literature. A theoretical section covers empirically based theoretical models like equations of state and CALPHAD models, the growing practice of using molecular dynamics and density functional theory simulations to fill gaps in measured data, and the use of artificial intelligence and machine learning prediction tools. Concluding, we review how a lack of measurement methods leads to gaps in data availability, which leads to data-driven theoretical models having higher uncertainty, thus limiting confidence in optimizing designs via numerical simulation for critical emerging technologies in extreme environments.

中文翻译：

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用于了解极端环境中金属的声速


了解材料行为对于成功的设计至关重要，尤其是考虑到在极端环境中运行的下一代能源、国防和制造系统的数量不断增加。极端环境中材料的具体应用包括聚变能、半导体制造、金属增材制造和航空航天。随着应用的增加，对极端环境中材料的基础科学的认识势在必行。声速有助于深入了解相边界，例如冲击诱导的熔化。声速的热力学积分可以推断出其他难以准确测量的理想特性，例如密度、热容和膨胀率。计量技术的进步使声速能够在高达 15 000 K 和 600 GPa 的极端条件下进行测量。这篇全面的评论介绍了最先进的声速计量技术，同时从历史的角度对其进行了背景分析。包括对新标准和计量最佳实践（包括不确定性报告）的详细讨论。介绍了凝聚态声速的数据可用性，突出了文献中的重大差距。理论部分涵盖基于经验的理论模型，如状态方程和 CALPHAD 模型、使用分子动力学和密度泛函理论模拟来填补测量数据空白的日益增长的实践，以及人工智能和机器学习预测工具的使用。 最后，我们回顾了缺乏测量方法如何导致数据可用性的差距，这导致数据驱动的理论模型具有更高的不确定性，从而限制了在极端环境中通过数值仿真优化关键新兴技术的设计的信心。