Observing Hydrogen’s Effects in Metal

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Hydrogen, the second-tiniest of all atoms, can penetrate right into the crystal structure of a solid metal.

Hydrogen, the second-tiniest of all atoms, can penetrate right into the crystal structure of a solid metal.

That’s good news for efforts to store hydrogen fuel safely within the metal itself, but it’s bad news for structures such as the pressure vessels in nuclear plants, where hydrogen uptake eventually makes the vessel’s metal walls more brittle, which can lead to failure. But this embrittlement process is difficult to observe because hydrogen atoms diffuse very fast, even inside the solid metal.

Now, researchers at MIT have figured out a way around that problem, creating a new technique that allows the observation of a metal surface during hydrogen penetration. Their findings are described in a paper appearing today in the International Journal of Hydrogen Energy, by MIT postdoc Jinwoo Kim and Thomas B. King Assistant Professor of Metallurgy C. Cem Tasan.

Read more at Massachusetts Institute of Technology

Image: This illustration depicts the main elements of the system the team used: The multicolored slab at center is the metal layer being studied, the pale blue region at left is the electrolyte solution used as a source of hydrogen, the small blue dots are the hydrogen atoms, and the green laser beams at right are probing the process. The large cylinder at right is a probe used to indent the metal to test its mechanical properties.  Courtesy of the researchers