Biodegradable magnesium (Mg) and some of its alloys are expected to degrade in the human body in consort with the bone tissue healing process. However, the rapid corrosion rate of Mg and its alloys in the physiological environment hinder their applications as implant materials. In this study, we fabricated a double-layer Ca-P coating on the surface of WE43 Mg alloy with enhanced corrosion resistance. The WE43 alloy was firstly anodized and then coated with dicalcium phosphate dihydrate (CaHPO₄·2H₂O, DCPD) and hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂, HA) layers, consecutively. The coating morphologies and mechanical properties of the DCPD- and HA-coated samples were characterized using SEM, XRD, FTIR, microhardness and pull-out tests. The corrosion behavior of the coated and uncoated samples was assessed by immersion in modified simulated body fluid (m-SBF) and potentiodynamic polarization tests. Results indicated that the DCPD coating was transformed into a compact and crack-free HA coating through an alkali treatment. The microhardness and adhesion strength of the HA-coating were significantly enhanced compared to the other samples. The HA-coated WE43 exhibited the lowest hydrogen gas evolution, degradation rate and the highest corrosion resistance in m-SBF among all samples.

预计可生物降解的镁（Mg）及其某些合金在人体中会随着骨骼组织愈合过程而降解。但是，Mg及其合金在生理环境中的快速腐蚀速率阻碍了它们作为植入材料的应用。在这项研究中，我们在WE43镁合金的表面上制造了具有增强耐腐蚀性的双层Ca-P涂层。首先对WE43合金进行阳极氧化，然后用磷酸二钙二水合物（CaHPO ₄ ·2H ₂ O，DCPD）和羟基磷灰石（Ca ₁₀（PO ₄）₆（OH）₂）进行涂层。，HA）层。使用SEM，XRD，FTIR，显微硬度和拉拔测试对DCPD和HA涂层样品的涂层形态和力学性能进行了表征。通过浸入改进的模拟体液（m-SBF）和电势极化测试中，评估了涂层和未涂层​​样品的腐蚀行为。结果表明，通过碱处理将DCPD涂层转变为致密且无裂纹的HA涂层。与其他样品相比，HA涂层的显微硬度和粘附强度显着提高。在所有样品中，HA涂层的WE43在m-SBF中表现出最低的氢气释放，降解速率和最高的耐腐蚀性。