Kinetics of Nitridation of Dysprosium by Reactive Ball Milling
Dr. Darryl Butt
Nitrides have been considered for use as nuclear reactor fuels because of their high melting temperatures and improved thermal conductivities when compared to traditional oxide fuels. The conversion of metals into nitrides has typically involved very high temperatures, long dwell times and multiple synthesis steps. The complexity of this synthesis process, along with the reactivity of nitrides with oxygen, has hindered the use of nitrides as reactor fuels. Recently, reactive ball milling has been explored as an alternate synthesis route for the conversion of metals into phase pure nitrides. This simple, closed synthesis route is a more economical method of creating high purity nitrides. Although this conversion process has been demonstrated, little is know about the kinetics of the nitridation reaction. In this research the effect of milling intensity on the kinetics of the conversion of dysprosium into dysprosium nitride was studied through in-situ measurements of pressure and temperature during the nitridation process. The kinetics of the reaction was further explored by studying the powder morphology of the initial stages of the reactive milling process. This work demonstrates that reactive ball milling is capable of converting Dy metal into a high purity nitride at low temperatures in a short amount of time. This closed conversion process could offer a simple and economical alternative to the high temperature furnace processes that are typically used to synthesize nitrides.