热声耦合法制备氟化镁钠膜机制及其生物腐蚀性能

Formation Mechanism and Bio-corrosion Properties of NaMgF3 Film Fabricated by Temperature and Ultrasonic Coupling Method

摘要:

采用热声耦合法在Mg-Gd-Zn-Zr镁合金表面制备氟化镁钠膜，用点滴法、电化学法和析氢腐蚀法评定其耐蚀性，用扫描电子显微镜（SEM）及能谱仪（EDS）分析氟化镁钠膜表面形貌及成分。结果表明，热声耦合法制备的氟化镁钠颗粒尺寸细小；氟化镁钠膜的变色时间随工艺时间延长而增大；氟化镁钠膜显著提高镁合金在模拟体液（SBF）中的容抗弧半径和阻抗值，降低其腐蚀电流密度和析氢速率；氟化镁钠膜具有促进钙磷沉积作用，其降解形成的新氟化物 磷酸盐膜具有进一步保护镁合金基体作用。

Abstract:

The NaMgF3 films were fabricated on the surface of Mg-Gd-Zn-Zr magnesium alloy by TUCM. Their corrosion properties were evaluated by dripping test, electrochemical test and hydrogen evaluation test, respectively. The microstructure and chemical composition of NaMgF3 films were analyzed by SEM and EDS, respectively. The results show that the NaMgF3 particles formed by TUCM are fine. The color change time of NaMgF3 film increases with increasing the process time. Their capacitive reactance arc radius and impedance value are obviously greater than that of magnesium alloy, while their corrosion current density and average hydrogen evolution rate are significantly smaller that of magnesium alloy in SBF. The NaMgF3 film promotes the deposition of Ca and P on the surface of magnesium alloy in the SBF. The new complex film of fluoride and phosphate formed by the corrosion of NaMgF3 film in the SBF will continue to protect the magnesium alloy from the corrosion