摘要
采用铸锭冶金法制备 Cr、Zr 微合金化 Al-Zn-Mg-Cu-Yb 合金。通过电化学测试和静置腐蚀实验,结合 X射线衍射仪、金相显微镜、扫描电镜和透射电镜研究 Cr、Zr 微合金化 Al-Zn-Mg-Cu-Yb 合金中凝固结晶相的析出特征,及其对铸态合金腐蚀行为的影响机理。结果表明:3 种铸态 Al-Zn-Mg-Cu-Yb 合金中的枝晶主要由 AlCu Mg(S相)、AlCuYb 和 Mg(Zn,Cu,Al)(Sigma 相)组成,而 Cr 或 Zr 的添加导致 Sigma 相中 Cu 含量增多,Sigma 相电位提高,枝晶与铝基体之间的电位差减小,从而改善了铸态合金的耐腐蚀性能。与 Al-Zn-Mg-Cu-Yb 和Al-Zn-Mg-Cu-Yb-Cr 合金相比,Al-Zn-Mg-Cu-Yb-Zr 合金具有更高的耐蚀性,腐蚀形式由沿枝晶腐蚀转变为均匀腐蚀。
Cr and Zr microalloyed Al-Zn-Mg-Cu-Yb alloys were prepared by ingot metallurgy. The precipitation characteristics of solidified crystalline phase in Cr or Zr microalloyed Al-Zn-Mg-Cu-Yb alloys and its influence mechanism on the corrosion behavior of the as-cast alloys were studied by electrochemical test and static corrosion experiment, combined with the observation and analysis of X-ray diffraction, optical microscope, scanning electron microscope and transmission electron microscope. The results show that the dendrites of the three as-cast Al-Zn-Mg-Cu-Yb alloys are mainly composed of AlCu Mg (S phase), AlCuYb and Mg(Zn,Cu,Al)(Sigma phase). The addition of Cr or Zr leads to the increase of Cu content in Sigma phase, the increase of potential of Sigma phase and the decrease of potential difference between dendrites and aluminum matrix, which can improve the corrosion properties of the as-cast alloys. Compared with Al-Zn-Mg-Cu-Yb and Al-Zn-Mg-Cu-Yb-Cr alloys, Al-Zn-Mg-Cu-Yb-Zr alloy has higher corrosion resistance, and the corrosion form changes from intergranular corrosion to uniform corrosion.
作者
许永祥
方华婵
段志英
张茁
汪家瑜
朱梦真
朱凯
肖鹏
XU Yongxiang;FANG Huachan;DUAN Zhiying;ZHANG Zhuo;WANG Jiayu;ZHU Mengzhen;ZHU Kai;XIAO Peng(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Advance Research Center,Central South University,Changsha 410083,China)
出处
《粉末冶金材料科学与工程》
2022年第5期519-531,共13页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学青年基金资助项目(51501228)
湖南省自然科学基金资助项目(2015JJ3167)
中南大学大型仪器设备共享基金资助项目(CSUZC202109)
中南大学研究生自主创新项目(1053320192832)。