Experimental investigation on formability and microstructure of AZ31B alloy in electropulse-assisted incremental forming

摘要

Based on a CNC machine tool and a high-energy electropulse generator, a self-built experiment platform was employed to conduct electropulse-assisted incremental forming (EAIF) of AZ31B alloy. The experimental results show that the electroplastic effect increases with the increase of the root mean square (RMS) current density of electropulse, and the forming limit angle in EAIF have been up to 72° from the previous 39.6° without electropulse. The tests prove that the peak current density plays a leading role in determining the materials formability when the RMS current density remains to be approximate. In addition, the microstructure transformations of the formed specimens were studied by means of optical microscopy and scanning electron microscopy. It is found that the electropulse can reduce the AZ31B dynamic recrystallization (DRX) temperature and accelerate the DRX progress, and it can also restrain the crack growth of the tested materials which in turn improves its formability.