Application of a new method for strain measurement in complex forging

In order to solve the difficulties in analysing the behaviour of metal flow quantitatively in forging. A new method, screw method for strain measurement was used inside plastic deformation body. Based on the study of compressor impeller, a set of dies were designed, and the female die was assembled with four die sections. At last, the impeller was formed by isothermal precision forge. Using this method, four typical flow lines, axial strain and radial strain were measured during forming of the compressor impeller. The quantitative results of strain distribution were obtained. This method is an effective technique to analyse metal deformation behavior and strain distribution during die forging. It can be used to study material flow and to predict strain distribution in general bulk metal forming.