基板温度对真空热蒸发沉积纯锌镀层组织性能的影响

Influence of Substrate Temperature on the Microstructure and Properties of Zinc Coatings Deposited by Vacuum Thermal Evaporation

通过真空热蒸发技术沉积得到一种耗锌量少且性能良好的锌镀层,研究了不同基板温度对所得锌镀层组织形貌、微观结构、腐蚀行为和附着力的影响。结果表明,当基底温度低于100℃时,镀层中存在排列紧密的柱状晶,当基板温度超过150℃后,镀层的微观结构发生明显变化。随着基板温度的升高,镀层表面电子转移的阻抗降低,基板温度为100℃时所得镀层的自腐蚀电位较正。随着基板温度的升高,镀层的附着力呈现先降低后增强的趋势,在25℃和50℃下沉积的镀层试样以及GI镀层试样中出现较为明显的镀层剥离现象。

A type of zinc coating was prepared by vacuum thermal evaporation technology,which consumesless zinc and has better performance.The morphology,microstructure,corrosion behavior and adhesion strength ofthe obtained zinc coatings were investigated.The results show that densely arranged columnar crystallites existed inthe coating when the substrate temperature was lower than 100℃,and the microstructure of the coatings changeddrastically when the substrate temperature exceeded 150℃.The impedance of the electron transfer process on thecoating surface decreased with the increase of the substrate temperature,and the self-corrosion potential of thecoatings obtained at the substrate temperature of 100℃was most positive.The adhesion strength of the coatingshowed a trend of first decreasing and then increasing,and there was obvious delamination appeared in the samplesdeposited at 25℃and 50℃,as well as the GI coating.