Pulse current assisted solid granules medium forming of nanocrystalline Ni foil

In order to improve the low-temperature forming performance of nanocrystalline Ni foil, a pulsed current-assisted solid granules medium forming process was proposed. In this paper, uniaxial tensile stress relaxation experiments at different temperatures and general solid granules medium forming experiments were carried out, and the forming temperature of nanocrystalline Ni foil was determined to be 300℃. The solid granules medium forming experiments were conducted at different peak current densities, and when the peak current density reached 150A/mm², the ratio of height to diameter of the formed part was 34%, and the wall thickness distribution was uniform. The introduction of pulsed current increases the forming efficiency by more than 4 times, and the surface of the formed part was not oxidized, and the quality was better. The effect mechanism of pulse current was studied. The results showed that the introduction of pulse current could promote the movement of dislocations, accelerate the diffusion rate of atoms at grain boundaries, and promote grain slip and grain rotation, thus improving the forming properties of the material.