Work-Hardening and Strain Rate Sensitivity of Flow Stress in High Purity Ice Single Crystals.
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
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Single crystals of high purity ice deformed by uniaxial compression on an Instron machine showed remarkable work- hardening after about 8 strain. By changing the strain rate during compression tests in the plastic region of the stress-strain curve, an apparent activation volume V and a dislocation mobility exponent m were calculated from the strain rate sensitivity of flow stress. The large work-hardening and the rapid increase in the value of m beyond about 10 strain indicate that the plastic flow in this region is controlled by dislocation intersections and nonconservative motion of jogs. Author
- Snow, Ice and Permafrost