Effect of Zr addition on microstructure and properties of Al-Mn-Si-Zn-based alloy
(1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Huafon Nikki Al Co., Ltd., Shanghai 201506, China)
2. Huafon Nikki Al Co., Ltd., Shanghai 201506, China)
Abstract: Effects of Zr addition on the microstructure, mechanical and electrochemical properties of Al-Mn-Si-Zn alloy were investigated. Transmission electron microscopy (TEM) observations reveal that, in as-annealled state, the precipitates in the Zr-containing alloy are finer and more dispersive than those in the Zr-free alloy. Whereas, in simulated brazing state, a weaker precipitation is found in the Zr-containing alloy. Tensile testing results indicate that, with Zr additon, comprehensive mechanical properties of the as-annealed alloys could be significantly improved but weakened for the simulated brazing alloy. Electrochemical testing results reveal that, with Zr addition, the corrosion resistance of the as-annealed alloy decreases. However, after the simulated brazing treatment, such a negative effect of Zr element on the corrosion behavior of the alloy could be negligible.
Key words: aluminium alloy; Zr alloying; precipitation; corrosion; mechanical property