Influence of grain boundaries on creep of KBr

Most creep experiments on alkali halides have used single crystal specimens, and only relatively little information is available on the creep characteristics of polycrystalline materials (primarily LiF and NaCl). In addition, there is the possibility of marked differences in impurity content between the single and polycrystalline samples, which make it difficult to compare the limited data at present available. Accordingly, this paper describes a series of experiments conducted on KBr with the objective of overcoming these difficulties. The specific aims of this work were threefold. First, to conduct creep tests on KBr single crystals in <100> orientation. Second, to prepare polycrystalline samples of KBr from the same source of single crystals. Third, to conduct creep tests on the polycrystalline material for a direct comparison with the single crystal data