齿科钴铬-镍铬合金激光焊接后耐腐蚀性评价

Corrosion resistance of laser-welded dissimilar dental alloy Co-Cr and Ni-Cr alloy

目的:研究激光焊接钴铬-镍铬合金的体外电化学行为及离子释出情况。方法:在体外模拟口腔环境中,测出激光焊接钴铬-镍铬合金阳极极化曲线及特征指数;检测激光焊接镍铬-钴铬合金在不同时间的离子释出情况,以钴铬合金、镍铬合金为对照。结果:钴铬合金自腐蚀电位低于镍铬合金,激光焊接钴铬-镍铬合金的自腐蚀电位、维钝电流密度、破裂电位介于前两者之间;激光焊接镍铬-钴铬合金,镍离子释出量7日后少于镍铬合金,钴离子释出量始终高于镍铬合金。结论:激光焊接钴铬-镍铬合金后,钴铬合金的阳极保护作用可减少镍铬合金镍离子释出,有助于改善镍铬合金生物相容性;激光焊接钴铬-镍铬合金,对其整体耐腐蚀性未有较大影响。

Objective： To evaluate the electrochemical corrosion characteristics and elemental release of laser-welded dissimilar alloy in dentistry： Co-Cr and Ni-Cr alloy in vitro. Methods： In simulated oral environment, the anodic polarization curve were determined and the element release of each metal after immersion in artificial saliva for ld, 2d, 3d, 4d, 7d, 10d, 14d, 21d, 35d, 60d were measured in comparison with dental Co-Cr alloy and dental Ni-Cr alloy. Results： The results showed that Ecorr of Co-Cr alloy was lowe than Ni-Cr alloy. The Ecorr, Ip, Eb of laser-welded group were between Co-Cr and Ni-Cr alloy groups; More Ni release was detected in laser-welded group than Ni-Cr alloy group after 7 days and its Co release was always more than Co-Cr alloy. Conclusions： The Co-Cr alloy had anodic protection to Ni-Cr alloy and decreased Ni release from Ni-Cr Alloy. The laser-welded had no obvious effect on anticorrosive property of Co-Cr and Ni-Cr alloy.