(1. 南京工程學院 材料工程學院,南京211167;
2. 江蘇康尚醫(yī)療器械有限公司,丹陽,212300)
摘 要: 采用浸泡法在Mg-Nd-Zn-Zr鎂合金表面制備氟化鎂鈉膜,采用點滴法、電化學法和浸泡法評定鎂合金基體和氟化鎂鈉膜的耐蝕性,采用掃描電鏡(SEM)和能譜儀(EDS)分析氟化鎂鈉膜試樣腐蝕前后的形貌及成分。結果表明,提高轉化處理溫度可顯著減小氟化鎂鈉顆粒尺寸,而轉化處理時間對顆粒尺寸影響較小;氟化鎂鈉顆粒通過二維形核后的臺階生長機制和螺旋生長機制長大;氟化鎂鈉膜可顯著降低Mg-Nd-Zn-Zr鎂合金在模擬體液中的平均析氫速率,在模擬體液中,氟化鎂鈉膜逐漸轉變?yōu)榉锖土姿猁}混合膜層,新膜層繼續(xù)起到保護鎂合金基體的作用。
關鍵字: 鎂合金;NaMgF3膜;模擬體液;析氫速率;腐蝕機制
(1. School of Material Engineering, Nanjing Institute of Technology, Nanjing 211167, China;
2. Jiangsu Konsung Equipment Co., Ltd., Danyang 212300, China)
Abstract:The NaMgF3 films on the surface of Mg-Nd-Zn-Zr magnesium alloy were fabricated by immersion method. Their corrosion properties were valuated by dripping test, electrochemical test and immersion method, respectively. The microstructures of the original and corrosive samples were observed by SEM and their chemical compositions were analyzed by EDS. The results show that the size of NaMgF3 particle is obviously reduced with the increase of conversion treatment temperature; however, it is little affected by the conversion treatment time. The NaMgF3 particles grow by two-dimensional nucleation, step growth mechanism and screw growth mechanism. The average hydrogen evolution rate of Mg-Nd-Zn-Zr magnesium alloy in simulated body fluid (SBF) solution can be significantly decreased by NaMgF3 film. The NaMgF3 films gradually transform into a new film consisting of fluoride and phosphate in the SBF solution, which will continue to protect the magnesium alloy from the corrosion.
Key words: NaMgF3 film; SBF; magnesium alloy; hydrogen evolution rate; corrosion mechanism


