A number of industrial and biomedical fields, such as hydraulic fracturing balls for gas and petroleum exploitation and implant materials, require Mg alloys with rapid dissolution. An iron-bearing phosphate chemical conversion (PCC) coating with self-catalytic degradation function was fabricated on the Mg alloy AZ31. Surface morphologies, chemical compositions and degradation behaviors of the PCC coating were investigated through FE-SEM, XPS, XRD, FTIR, electrochemical and hydrogen evolution tests. Results indicated that the PCC coating was characterized by iron, its phosphates and hydroxides, amorphous Mg(OH)₂ and Mg_3-n(H_nPO₄)₂. The self-catalytic degradation effects were predominately concerned with the Fe concentration, chemical composition and microstructure of the PCC coating, which were ascribed to the galvanic corrosion between Fe in the PCC coating and the Mg substrate. The coating with higher Fe content and porous microstructure exhibited a higher degradation rate than that of the AZ31 substrate, while the coating with a trace of Fe and compact surface disclosed a slightly enhanced corrosion resistance for the AZ31 substrate.

许多工业和生物医学领域，例如用于天然气和石油开采的水力压裂球以及植入材料，都需要具有快速溶解性的Mg合金。在镁合金AZ31上制备了具有自催化降解功能的含铁磷酸盐化学转化（PCC）涂层。通过FE-SEM，XPS，XRD，FTIR，电化学和析氢试验研究了PCC涂层的表面形貌，化学成分和降解行为。结果表明PCC涂层的特征是铁，其磷酸盐和氢氧化物，无定形Mg（OH）₂和Mg _{3- n}（H _n PO ₄）₂。自催化降解作用主要与PCC涂层中的Fe浓度，化学组成和微观结构有关，这归因于PCC涂层中的Fe与Mg基材之间的电化腐蚀。具有较高铁含量和微孔结构的涂层表现出比AZ31基体更高的降解速率，而具有微量铁和致密表面的涂层显示出对AZ31基体的耐腐蚀性稍有提高。