PLLA封孔工艺对微弧氧化镁合金丝材性能的影响

目的提高微弧氧化镁合金丝材的强度和耐腐蚀性能。方法通过硅烷偶联及聚乳酸封孔处理对微弧氧化AZ31B镁合金丝材进行表面改性,采用扫描电子显微镜(SEM)、电子能谱仪(EDS)以及模拟胃液(SGF)浸泡实验、拉伸实验等设备和方法,研究了硅烷偶联工艺、聚乳酸封孔工艺对丝材综合性能的影响。结果微弧氧化镁合金丝材的耐腐蚀性能随偶联处理时间的延长先升高后降低,当处理时间为90 min时,丝材的耐腐蚀性能最佳。随封孔聚乳酸浓度的升高,丝材的耐腐蚀性能先升高后降低,强度增大;随提拉速度的增大,其耐腐蚀性能和强度均逐渐提高;随浸渍提拉次数的增多,丝材的耐腐蚀性能和强度逐渐降低。当聚乳酸质量浓度为0.14 g/m L、提拉速度为0.9 cm/s、浸渍提拉次数为1次时,硅烷偶联处理过的丝材的综合性能最佳。结论微弧氧化镁合金丝材的性能可以通过聚乳酸封孔处理改善,改善效果与聚乳酸浓度、提拉速度和浸渍提拉次数有关。微弧氧化镁合金丝材表面硅烷偶联处理能有效提高聚乳酸封孔效果。

Effects of PLLA Sealing Technology on Performance of Micro-arc Oxidized Magnesium Alloys

The work aims to improve the strength and corrosion resistance of micro-arc oxidized biomedical magnesium alloys. Silane coupling treatment and poly-L-lactic acid (PLLA) sealing treatment were used to modify the surfaces of micro-arc oxidized (MAO) AZ31B magnesium alloy wires. Effects of silane coupling and PLLA sealing treatment on overall performance and degradation behaviors of MAO-wires were investigated by using scanning electronic microscopy (SEM), energy dispersive spectrometer (EDS), tensile tests and in vitro immersion tests with simulated gastric fluid (SGF). Silane coupling treatment to MAO-wires might improve the PLLA sealing effects. The corrosion resistance of the treated wires increased first and then decreased as the coupling time increased. The treated wires showed best corrosion resistance when the treatment lasted for 90 min. Corrosion resistance of the treated wires increased firstly and then decreased, and the strength increased as the PLLA concentration increased. Both the corrosion resistance and strength increased gradually as the pulling speed increased. Both the corrosion resistance and strength decreased gradually as the dipping times increased. The PLLA sealing treatment had no effects on the elongation of the treated wires. The treated wires showed the best overall performance when the PLLA concentration was 0.14 g/mL, the pulling speed was 0.9 cm/s, the dipping time was only one time. Corrosion resistance of the micro-arc oxidized (MAO) AZ31B magnesium alloy can be improved by poly-L-lactic acid (PLLA) sealing treatment effectively, and the effects relate to the concentration of PLLA, pulling speed and dipping times. The PLLA sealing effects can be improved by silane coupling treatment to MAO-wires.