锻造CoCrMo合金关节材料的摩擦腐蚀行为

采用UMT-2多功能摩擦磨损试验机和电化学工作站(CHI614E)考察了锻造Co Cr Mo合金在25%小牛血清溶液条件下的摩擦腐蚀性能,利用扫描电镜观察了摩擦腐蚀的形貌特征,对腐蚀损失量、机械磨损损失量及腐蚀和磨损的协同损失量进行了对比分析.结果表明:锻造Co Cr Mo合金的腐蚀电位(Ecorr)约-820 m V,在0.5~0.75 V区间出现二次钝化.不同载荷条件下,摩擦腐蚀的摩擦系数均大于纯摩擦系数,且随载荷的增加而减小,摩擦腐蚀电流则随载荷的增加而增大.随载荷的增加,机械磨损损失量所占比例增大,腐蚀损失量所占比例降低.摩擦腐蚀的协同损失量占到总损失量的30%以上,且随载荷增加而增大.

Tribocorrosion Behavior of Forged CoCrMo Alloy for the Artificial Joint Materials

The tribocorrosion behavior of forged CoCrMo alloy in 25% calf serum solution was investigated by the UMT-2 multi-functional friction and wear tester and electrochemical workstation (CHI614E). The morphology of tribocorrosion of forged CoCrMo alloy was analyzed by scanning electron microscopy. The corrosion loss,loss of mechanical wear and loss due to wear-corrosion synergistic interaction were compared systematically. The results show that the corrosion potential (E_corr) of forged CoCrMo alloy in 25% calf serum solution was about -820 mV. The two passivation phenomena occurred in 0.5~0.75 V region. Under the different applied load conditions,the friction coefficients of tribocorrosion were higher than that of the pure sliding. With the increase of applied loads,the friction coefficients of tribocorrosion decreased and the current increased. The loss of mechanical wear increased and the corrosion loss decreased with the increase of applied loads. The loss due to wear-corrosion synergistic interaction accounted for more than 30% of the total loss.