IUCr journals

Combustion front dynamics in the combustion synthesis of refractory metal carbides and di-borides using time-resolved X-ray diffraction

J. Synchrotron Rad. (2006). 13, 326–335 [doi.org/10.1107/S0909049506020796]

[Diffraction-reaction chamber]Time lapsed photos for the combustion synthesis of Zr + C → ZrC in the diffraction-reaction chamber. Top: half-way through the combustion after ignition with the tungsten coil powered off. Bottom: at completion of combustion. The combustion front was moving from right to left at a velocity of 5.8 mm s-1 as recorded with a video camera.
Synchrotron time-resolved diffraction was used to elucidate the combustion dynamics of refractory metal carbides and diborides (Figure). The combustions completed within 200–400 ms with no detectible intermediates. The Ti, Zr and Hf systems involved a liquid phase with a typical combustion front velocity of 5–6 mm s-1. The Nb and Ta systems have no liquid phase with a combustion front velocity of 1–2 mm s-1, and are truly solid combustion systems. This study provides a new avenue to chemical dynamics and macrokinetics of high-temperature solid-state reactions.

Joe Wong, E.M. Larson, P. A. Waide and R. Frahm