Lithium corrosion resistance of aluminum nitride prepared by structural doping with various elements

Abstract

Influences of various doping elements on the corrosion behavior and possible failure mechanism of aluminum nitride ceramic in lithium had been investigated using X-ray diffraction and scanning electron microscope techniques. The results showed that different doping element could produce obvious effects on the corrosion behavior of aluminum nitride. In comparison with yttrium doping, better corrosion resistance in lithium could be achieved in zirconia doped aluminum nitride. This was attributed to a certain degree of compatibility of both the doped zirconium and its related compounds with lithium. Based on these observations, a corrosion resistance mechanism model was proposed, in which lithium was supposed to be hindered from diffusing into aluminum nitride by a network structure with the impurities, ie. ZrN and Al2.85N0.5O3.5, as the nodes. The corrosion resistance could also be improved effectively by fine and homogeneous grains due to the influences of grain sizes on the node number in network structure. Further studies on the corrosion behavior in embedded liquid lithium implied that the severity of corrosion had close relations with the sample surface quality.