Research on the deformation behavior of pure zinc fabricated by forward extrusion and composite extrusion

Zinc and its alloys are biomedical biodegradable materials with broad application prospects. In this paper, commercially pure zinc bars were subjected to two different types of extrusion treatments, forward extrusion (FE) and composite extrusion (CE), at 120 degrees C to study the changes in microstructure and mechanical properties. Compared to the virgin annealed state of pure zinc, the yield strength of CE decreased significantly from 73.67 MPa to 40.87 MPa, while the elongation of FE increased markedly from 9.23 % to 59 %. The anomalous phenomenon of decreasing strength and increasing ductility of extruded pure zinc is significantly different from that of extruded zinc and magnesium alloys. To investigate the reason for this anomaly, a detailed study of the microstructure evolution of pure zinc under three processing states was carried out using EBSD. Grain growth and texture weakening lead to a loss of strength, whereas the increase in ductility after extrusion is attributed to the activation of more slip systems.