A New Sight of the Growth Characteristics of Solidified Al3Ni at the Liquid–Solid Interface by Synchrotron Radiography and 3D Tomography

Production of a new 3D electrode skeleton of Ni with very high electrochemical surface area for oxygen evolution

“…On the other hand, Z. Ding et al did not observe Al3Ni fibers during the heat treatment process (the second step in Fig. 1) and, their results showed that Al3Ni fibers are just produced during the cooling down [19]. The reason why more nickel is dissolved into the melt is related to the interaction enthalpy of Ni and Al.…”

“…Because Al3Ni does not ideally grow perpendicular to the Ni plate and pole figure was got from top surface of sample. Z. Ding et al [19] investigated growth characteristic of Al3Ni produced after interaction at 850℃. They illustrated {001} plane of Al3Ni grows in direction of [001] that their results are not similar to our results.…”

“…After leaching to form Al3Ni (D2 layer) via a peritectic reaction [19]. Therefore, in the first area of Fig.…”

“…If there is enough weight of Al powder, some molten Al remain on the surface while Ni is dissolving into it. In this situation, Al oxide can be seen on the surface of the melt [19]. During Ar discharging (cooling down), Al3Ni fibers are nucleated on the surface of Al3Ni layer (D2) and grow upward away rapidly in the molten alloy.…”

“…The reason could be related to the high melting entropy and the strong growth anisotropy of Al3Ni fibers. In the next step, when growth of Al3Ni is stop in direction of its length, Al3Ni may grow along its width or maybe several Al3Ni are combined to form a primary Al3Ni (coarse structure) [19]. By growing Al3Ni, the molten alloy is depleting from Ni.…”