| Abstract Scope |
Many people are familiar with the fact that concrete is quite weak in tension but is strong enough for building infrastructure in compression. Other materials, including ceramics and amorphous metals, exhibit stress-state-dependent mechanical behavior, too. Complex stress states suppress certain deformation mechanisms and promote others, providing a way to alter a material’s mechanical response to enable new engineering applications. In this talk, I will discuss the impacts of complex stress state on mechanical behavior in rare earth orthophosphates ceramics, which we have elucidated using diamond anvil cells with in situ Raman spectroscopy, x-ray diffraction, and photoluminescence spectroscopy. Superimposed shear stress dramatically reduces the onset pressure of a phase transformation in these materials by facilitating the distortion of the network of polyhedral units. The interesting mechanical behavior of rare earth orthophosphates intersects a diverse range of topics, including asteroid impacts and geochronology, optically probed environment sensing, and high-temperature ceramic matrix composites. |