Microstructure, Mechanical, and Corrosion Performance of AA4343/AA3003/AA4343 Laminated Sheets Subjected to Cryorolling and Annealing

Abstract

The effects of cryorolling (CR), hot rolling (HR), and different annealing temperatures on the microstructure, mechanical, and corrosion performance of AA4343/AA3003/AA4343 laminated sheets are studied. Compared with the HR samples, the microstructure of the CR samples presents a significant decrease in the size of elongated grains and significantly large second‐phase particles Al(Mn, Fe)Si in the AA3003 alloy. Grains in CR samples subjected annealing at 200–300 °C become finer. Increasing to 400–550 °C, the grains begin to grow, and the Si is diffused into the core layer. A comparison of HR and CR processing reveals a significant increase in the yield strength from 153 to 209 MPa and the ultimate tensile strength from 168 MPa to 217 MPa of the laminated sheet. Potentiodynamic polarization measurements and immersion tests are conducted to assess the corrosion morphology. After being immersed in a 3.5% NaCl solution for two weeks, the clad surface of the laminated sheet exhibits uniform corrosion products and pitting corrosion, which shows the pitting corrosion depth of the CR sample improved compared to the HR sample. The study suggests that both CR and annealing can be useful for enhancing the mechanical properties, and corrosion morphology of laminated sheets.