Chen Yang, Yin Zheng, Yan Hong, Zhou Guo-Hua, Wu Xiao-Quan, Hu Zhi
Institute of Advanced Forming, Nanchang University, Nanchang 330031, China.
Key Laboratory of Light Alloy Preparation & Processing in Nanchang City, Nanchang 330031, China.
Materials (Basel). 2018 Nov 20;11(11):2331. doi: 10.3390/ma11112331.
The effects of samarium (Sm) on the microstructure and corrosion behavior of AZ91 magnesium alloy treated by ultrasonic vibration were investigated by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and electrochemical measurements. The results showed that the addition of Sm resulted in the formation of Al₂Sm, which reduced the volume fraction of the β-MgAl phase and changed its morphology to fine granular. The AZ91⁻Sm alloys treated by ultrasonic vibration revealed relatively lower weight loss, hydrogen evolution, and corrosion current density values compared to the ultrasonic-treated AZ91 alloy prepared without Sm. Locally, a coarse β phase in the ultrasonic-treated AZ91 alloy accelerated the possibility of micro-galvanic corrosion growing into the matrix. In the prepared AZ91⁻Sm alloys treated by ultrasonic vibration, the fine β and Al₂Sm phases reduced the probability of micro-galvanic corrosion growth and, therefore, formed a uniform corrosion layer on the surface of the alloys.
通过扫描电子显微镜、X射线衍射、透射电子显微镜和电化学测量等手段，研究了钐（Sm）对超声振动处理的AZ91镁合金微观结构和腐蚀行为的影响。结果表明，添加Sm导致形成Al₂Sm，这降低了β-MgAl相的体积分数，并使其形态变为细颗粒状。与未添加Sm制备的超声处理AZ91合金相比，经超声振动处理的AZ91-Sm合金显示出相对较低的重量损失、析氢量和腐蚀电流密度值。局部而言，超声处理的AZ91合金中的粗大β相加速了微电偶腐蚀向基体扩展的可能性。在制备的经超声振动处理的AZ91-Sm合金中，细小的β相和Al₂Sm相降低了微电偶腐蚀扩展的概率，因此在合金表面形成了均匀的腐蚀层。
