CAJ | 학술논문

通过尿素水解法在AZ31镁合金表面原位合成纳米尺度的层状双金属氢氧化物(水滑石)转化膜，并提出成膜机理。首先，溶解的Mg2+离子沉积形成含有MgCO3和Mg5(CO3)4(OH)2·4H2O的前驱体膜；然后，前驱体膜在碱性条件下转化为高结晶的 Mg(OH)2；最后，Mg(OH)2中的 Mg2+离子被 Al3+离子取代，Mg(OH)2转化为更稳定的水滑石层状结构，同时层间 OH?与溶液中的2?3CO 发生离子交换，因此形成水滑石(Mg6Al2(OH)16CO3·4H2O)膜。结果表明，以互锁的片状纳米结构和离子交换性能为特征的水滑石膜可以有效提高AZ31镁合金的耐蚀性。
통과뇨소수해법재AZ31미합금표면원위합성납미척도적층상쌍금속경양화물(수활석)전화막，병제출성막궤리。수선，용해적Mg2+리자침적형성함유MgCO3화Mg5(CO3)4(OH)2·4H2O적전구체막；연후，전구체막재감성조건하전화위고결정적 Mg(OH)2；최후，Mg(OH)2중적 Mg2+리자피 Al3+리자취대，Mg(OH)2전화위경은정적수활석층상결구，동시층간 OH?여용액중적2?3CO 발생리자교환，인차형성수활석(Mg6Al2(OH)16CO3·4H2O)막。결과표명，이호쇄적편상납미결구화리자교환성능위특정적수활석막가이유효제고AZ31미합금적내식성。
In situ growth of nano-sized layered double hydroxides (LDH) conversion film on AZ31 alloy was synthesized by a urea hydrolysis method. The formation mechanism of the film was proposed. Firstly, the dissolved Mg2+ions deposited into a precursor film consisted of MgCO3 and Mg5(CO3)4(OH)2·4H2O; secondly, the precursor translated into the crystalline Mg(OH)2 in alkaline conditions; finally, the Mg2+ ions in Mg(OH)2 were replaced by Al3+ ions, Mg(OH)2 translated into the more stable LDH structure, simultaneously, the OH? ions in the interlayer were exchanged by2?3CO, thus led to the formation of the LDH (Mg6Al2(OH)16CO3·4H2O) film. The results indicated that the LDH film characterized by interlocking plate-like nanostructures and ion-exchange ability significantly improved the corrosion resistance of the AZ31 Mg alloy.