First in class study of high-strain rates in Mg features new, fast detector

Arthur Woll, CHESS, Cornell University

The structural evolution of materials under sudden, high impact deformation is of critical importance in a variety of different applications, particularly in the automotive and aerospace industries.

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Figure 1. Dr. Emily Huskins at the G3 hutch at CHESS in early 2014, preparing the Kolsky-bar apparatus.

But despite this importance, existing methods to probe such events, involving strain rates of 103-105 s-1, provide only limited or indirect information about the atomic-scale rearrangement that materials undergo.

By combining the high x-ray intensity of synchrotron radiation with a new, high-speed pixel array detector developed at Cornell, researchers from six different institutions have demonstrated a new approach to this critical area of materials science. Using a so-called Kolsky bar apparatus at the G3 hutch at CHESS, the group was able to obtain in situ diffraction patterns of magnesium undergoing shock-wave induced strain, with useful exposures as short as 70 ns. The results are described in detail in a new publication in Review of Scientific Instruments, (v. 85, 093901 (2014), and are also described briefly in an online highlight by the Army Research Lab.