【摘要】 利用金相、SEM、TEM、XRD、盐雾、电化学测量系统研究了镁合金AZ91D的化学镀Ni-P镀层组织结构及耐蚀性能,结果表明,化学镀镍层为胞状致密结构,镀层厚度均匀,与基体结合良好。P的质量分数为6. 68 %,为中P镀层,镀层阻抗为0. 6Ω,镀层组织为非晶加少量微晶;镀层耐腐蚀性能良好,连续盐雾8h未出现腐蚀斑点。盐雾腐蚀速率明显低于基体的腐蚀速率。化学镀镍磷层的最小腐蚀电流密度为4. 52μA/cm2,腐蚀电位为-250mV。低于200℃退火,镀层的耐腐蚀性能有所提高,而高于200℃退火,其耐腐蚀性能随温度提高而降低。更多还原

【Abstract】 Studied microstructures and corrosion resistance of electroless Ni-P on AZ91D magnesium alloy through metallography,SEM,TEM,DSC XRD,smog experiment and polarized experiment analysis.The result was drawn that electroless coating is composed of compact cells structures,coating thickness is symmetrical,the adhesion resistance is good,phosphor content is 6.68 %,which belongs to medium phosphor coating,the impedance is 0.6 Ω. The coating has a constitution of amorphous with few minicrystal,resistance is very well,coating has not appear to corrosion spots at salt mist for continuous 8 h.Polarized experiment indicated that the lowest corrosive current of initial coating is 4.52 μA/cm~2,and corrode electric potential Ecorr is -250 mV.While the annealed temperature is lower than 200 ℃,the corrosion-resistant performance of plating layer improves to some extent,annealed at higher than 200 ℃,corrosion-resistant performance has a downward trend wholly.更多还原