脉冲磁场对镁铜合金组织、力学性能及生物腐蚀行为的影响

Effects of pulsed magnetic field on microstructure, mechanical properties and bio-corrosion behavior of Mg-0.6Cu alloy

在生物医用Mg-0.6Cu合金的凝固过程中施加脉冲磁场处理,研究脉冲电压对合金凝固组织、力学性能及生物腐蚀行为的影响。结果表明:随着放电电压的增加,在合金凝固组织逐渐细化的同时,第二相的数量也逐渐降低;当脉冲电压为300 V时,合金的屈服强度、抗拉强度和伸长率均逐渐提高,其较未处理合金分别提高了49.4%、45.7%和114.3%;试样在37℃的SBF溶液中的析氢速率、腐蚀速率和自腐蚀电流密度均逐渐降低,同时,其自腐蚀电位也逐渐向正向移动,这表明合金的耐腐蚀性能逐渐提高。

The pulsed magnetic field(PMF)has been imposed during solidification of biodegradable Mg-0.6Cu alloy.The effects of discharging voltage on the solidification microstructure,mechanical properties and bio-corrosion behavior of Mg-0.6Cu alloy were studied.The results show that the solidification microstructure of Mg-0.6Cu alloy is further refined with the increase of the discharging voltage.Moreover,the volume fraction of second phase in the alloy is reduced by PMF.The mechanical properties of Mg-0.6Cu alloy are enhanced.The yield strength,ultimate tensile strength and elongation of the alloy treated by PMF at discharging voltage of 300 V are increased by 49.4%,45.7%and 114.3%,respectively,compared to those of the alloy untreated by PMF.The PMF treatment is beneficial to the bio-corrosion resistance improvement of Mg-0.6Cu alloy.With the increase of the discharging voltage,the hydrogen evolution rate,corrosion rate and corrosion current density of the alloys gradually decrease,and the corrosion potential of the alloys,meanwhile,gradually move towards positive direction.