【摘要】 利用化学沉积法在镁铝合金表面构筑锶磷化膜,以氢氧化钠和硅酸钠为原料配制磷化膜封孔处理液,对镁合金表面锶磷化膜存在的裂纹和孔洞等缺陷进行封孔处理。通过元素分析及扫描电子显微镜发现改性膜层表面具有Sr、P、O以及Si元素,硅酸钠对锶磷化膜具有良好的封孔作用。通过膜层厚度检测,证明封孔后的锶磷化膜厚度没有发生显著变化。封孔后的锶磷化膜极化电阻比封孔前提升了4倍,而腐蚀电流仅为封孔前的1/3,封孔后膜层的耐腐蚀性能显著提升。更多还原

【Abstract】 The magnesium-aluminum alloy surface was modified with an strontium phosphate film by chemical deposition method.Then,sodium hydroxide and sodium silicate were used to prepare strontium phosphating film sealing treatment solution,which could seal the cracks,holes and other defects of strontium phosphate coating on the surface of the magnesium alloy. The results showed that the films had obvious Si elements with Sr,P and O elements,and the microstructures of the films showed that the sodium silicate had good sealing effect on the strontium phosphating film. The result of film thickness detection showed that there was no obvious change on the thickness of the strontium phosphating film. The electrochemical test showed that the strontium phosphating film had a four-fold increase in the polarization resistance before sealing,while the corrosion current was only one-third of that before the sealing,and the corrosion resistance of the film after sealing was significantly improved.更多还原