组件式设计常被用于人工髋关节,钴铬钼合金(CoCrMo)与钛合金(Ti6Al4V)的压配合最常用.本文应用电化学方法研究了静态条件下两种合金的电偶腐蚀行为.浸泡实验表明,钴络钼合金为阳极,但电偶电流与其维钝电流相近,并无明显加速腐蚀效应;钛合金为阴极,受到保护.失重及金相观察结果显示,在45天的浸泡实验周期内,未发现腐蚀痕迹.混合电位理论和电位保护理论分析结果显示,这两种合金在静态条件下具有很弱的电偶腐蚀敏感性,其电偶腐蚀电位处于两种合金的钝化电位区,电偶电流为合金的维钝电流.
The combination of Co-Cr-Mo alloy and Ti_6Al_4V alloy is widely used as total hip prostheses. The objective of this work is to quantify the possibility of the acceleration of corrosion due to the galvanic effect. Electrochemical tests based on mixed potential and protection potential theories were used to study the galvanic corrosion behavior of coupling these alloys. The results indicated that the galvanic potential between two alloys always was in the passive potential zone of the isolated alloy respectively, and that the galvanic current of the couple is same as the corrosion current of isolated alloy under passive state. The effect of galvanic coupling on corrosion rate is not significant. These results were verified by direct coupling experiments. There is not weight loss of alloys measured by the analysis balance after immersion in saline solution for 45 days. Observation with optical microscope showed no extensive corrosion appearance for two alloys.
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