Non-ergodic Processes in Athermal Martensitic Alloys Revealed by X-ray Photon Correlation Spectroscopy: Bulk Properties. (2015)

• Record Type: Journal Article
• Authors: Widera, M.; Sprung, M.; Klemradt, U.
• Is Part Of: Materials today. Volume 2(2015)Supplement 3
• Page Start: S929
• Page End: S932
• Publication Date: 2015
• Subjects: slow time-dependent phenomena -- aging -- incubation time -- symmetry-conforming short-range-order model -- X-ray photon correlation spectroscopy -- microstructural avalanches; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2015.07.434
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: The vast majority of martensitic transformations (MT) is classically viewed as being athermal, although time-dependent phenomena such as incubation time and/or aging effects have been known for a long time. Using highly coherent X-rays it has become possible to access non-equilibrium, intermediate states of the MT. X-ray photon correlation spectroscopy (XPCS) can reveal non-equilibrium dynamics using two-time correlation functions, where fluctuating intensities of X-ray speckle pattern are auto-correlated. Here we report XPCS experiments on a Ni63 Al37 alloy. The revealed isothermal dynamics shows non-equilibrium features on long time scales, superimposed with microstructural avalanches. The dynamics supports the "symmetry conforming short-range-order" model based on short range diffusion.