Interaction of Mobile Dislocation with Additives in Ionic Crystals

The mechanical properties of materials are affected by the interaction of mobile dislocation with additive ions. Although this has been widely investigated by various methods (yield and proof stress measurements, microscopy observations of dislocation, internal friction measurements, stress relaxation tests and so on), it is difficult to obtain the information on mobile dislocation-additives interaction during plastic deformation of bulk. While, the strain-rate cycling tests between two strain-rates of 1.1×10⁻⁵ s⁻¹ and 5.5×10⁻⁵ s⁻¹ with ultrasonic oscillations (original method) would overcome the weak points of them. The original method is considered to give the information of dislocation mobility on the slip plane contained mainly with two kinds of obstacles: forest dislocations and additive ions. Some results will be presented here.

Keywords: Dislocation; Point defects; Plastic deformation; Ultrasonic oscillation; Strain rates