Effect of processing variables on the reaction kinetics of MgB2 fibers

The reaction kinetics for converting B fibers into MgB2 fibers are measured by in situ synchrotron X-ray diffraction and ex situ by metallography as a function of the following processing variables: fiber diameter, fiber doping, fiber surface treatment, Mg flux (liquid or gaseous Mg), and thermal cycling. Changes to the fiber diameter, surface treatment and Mg flux affect little the rates of the reaction, while C-doping of fibers dramatically decreases reaction rate and thermal cycling increases the reaction rate.