Measurement of Flow Stress for Pure Aluminum up to 10 in Strain

A stress-strain curve is generally measured by tensile testing or compression testing. In some metal forming processes, the maximum strain exceeds 5.0 (500%); however, the standard testing methods can only measure an stress-strain curve up to a strain of 1.0. Therefore, a new method was developed that enables us to measure a stress-strain curve for strains up to 10.0. High-pressure torsion was applied for the measurement. Using high-pressure torsion, it is possible to introduce larger strains than conventional methods. A stress-strain curve measurement was performed for pure aluminum. The stress-strain curve measured using the developed method was compared with that obtained using a compression test. It is confirmed that the flow stress was successfully measured up to a strain of 10.0. In addition, the results for the developed method correspond with that of the compression test up to a strain of 1.0.