采用光学显微镜(OM)、透射电镜(TEM)、电化学试验、拉伸试验、双悬臂梁(DCB)试验等方法,研究了Zr、Si含量对体育器材用Al-Zn-Mg合金组织、拉伸性能和在3.5% NaCl溶液中耐蚀性的影响。结果表明:添加微量Zr、Si对合金组织和性能均产生明显影响,复合添加Zr、Si比单独添加Zr效果更好;在合金中添加0.15% Zr后,合金晶粒尺寸明显减小,但部分再结晶晶粒长大;在合金中复合添加0.15% Zr和0.08% Si后,合金晶粒尺寸进一步减小,且晶粒尺寸大小均一,呈等轴晶状;与未添加Zr、Si的合金相比,复合添加0.15% Zr和0.08% Si的合金的平均晶粒尺寸由177.8 μm降低到6.8 μm,抗拉强度和屈服强度由283.6 MPa和249.2 MPa提升至368.1 MPa和319.2 MPa,应力强度因子K_ISCC由3.2 提升至10.9,合金的抗电化学腐蚀性能显著提高。

Effects of Zr and Si content on the microstructure, tensile properties and corrosion resistance in 3.5% NaCl solution of Al-Zn-Mg alloys used for sports equipment were investigated by optical microscope (OM), transmission electron microscope (TEM), electrochemical test, tensile experiment and double cantilever beam (DCB) test. The results showed that the addition of Zr and Si had significant influences on the microstructure and properties. The combined addition of both Zr and Si was even more effective than the individual addition of Zr. When Zr content was 0.15%, the grain size significantly reduced but a small mount of coarse recrystallization grains were observed. The microstructure consisted of fine-scale equiaxed grains and had minimum grain size after the combined addition of 0.15% Zr and 0.08% Si. After adding 0.15% Zr and 0.08 % Si into the alloy, the average grain size decreased from 177.8 μm to 6.8 μm, the tensile strength and yield strength increased from 283.6 MPa and 249.2 MPa to 368.1 MPa and 319.2 MPa, respectively, the stress intensity factor K_ISCC increased from 3.2 to 10.9 and the electrochemical corrosion resistance of the alloy significantly improved.