Study on Microstructure Control and Properties of Al-Zn-Mg-Cu Alloy by Pulsed Electric Field
摘要
The effects of electric pulse treatment (EPT) on the mechanical properties and corrosion resistance of Al-Zn-Mg-Cu alloys were systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Vickers hardness testing, and electrochemical workstation analysis. The results indicate that EPT effectively refines the grain structure and mitigates elemental segregation, thereby enhancing both mechanical performance and corrosion resistance. Under a pulse voltage of 500 V, the average grain size of the alloy was reduced from 74 μm to 43 μm, and the area fraction of the η(MgZn2) phase decreased from 11.68% to 7.13%. Texture analysis revealed that the predominant orientations after treatment were {111} <011> and {111} <166> , with an increased fraction of equiaxed grains and low-angle grain boundaries, and the generation of a coarse η phase during solidification was suppressed. The microhardness of the alloy matrix increased from 130 HV0.2 to 166 HV0.2, the tensile strength improved from 131 MPa to 206 MPa, and elongation rose from 2.31% to 5.17%. Electrochemical measurements showed that the corrosion potential shifted positively from − 0.862 V to − 0.754 V, while the corrosion current density dropped from 8.362 × 10−3 A cm−2 to 2.46 × 10−6 A cm−2, a reduction of approximately three orders of magnitude.