Extended expanding cavity model for measurement of flow properties using instrumented spherical indentation

Abstract

We propose an extended expanding cavity model (ECM) in instrumented spherical indentation to evaluate flow properties measured in uniaxial mechanical testing. We describe the mean pressure of the projected surface from radial stress at the hemispherical core boundary with a scaling factor for strain-hardening metals. Plastic constraint factors determined by the strain-hardening exponent, yield strain and scaling factor successfully illustrate flow stress-strain points in uniaxial tension tests. We suggest a novel way to determine the strain-hardening exponent from the ratio of indentation loading slope, and a modified Meyer relation to measure yield strengths.