Creep Behavior of Potassium Chloride–Rubidium Chloride Solid Solution Alloys

The creep behavior of three KCl–RbCl solid solution alloys and pure KCl and pure RbCl single crystals compressed along the 〈100〉 direction was investigated at 600°C at stresses between 0.5 and 15 MPa. The reduced primary creep stage, a value of the stress exponent of about 3 for the KCl–20 mol% RbCl and KCl–30 mol% RbCl alloys versus about 5 for pure KCl and pure RbCl and the results of the stress reduction tests for these alloys are in good agreement with creep behavior observed in class I metallic solid solution alloys, where the creep rate is controlled by a dislocation glide process. The dislocation substructure developed in the KCl–RbCl alloys consisted of well‐developed subgrains.