Mareci D, Nemtoi Gh, Aelenei N, Bocanu C
Department of Physical Chemistry, Faculty of Industrial Chemistry, Technical University Gh. Asachi, Bd. D. Mangeron, No. 71, 700050 Iasi, Romania.
Eur Cell Mater. 2005 Jul 8;10:1-7; discussion 1-7.
Five non-precious Ni-Co based alloys were analyzed with respect to their corrosion behaviour. The correlation between the amount of the elements Cr, Mo, V and the corrosion behaviour, expressed by the PREN (pitting resistance equivalent number) index in the case of the allied steels, was extended for Ni-Cr and Co-Cr dental alloys characterization. Open circuit potential, corrosion current densities, as a measure of the corrosion rate, and main parameters of the corrosion process were evaluated from linear and cyclic polarization curves, for five Ni-Cr or Co-Cr alloys in an Afnor type artificial saliva. The maintenance times of the alloy in the corrosive medium influence the corrosion rate; the corrosion current values decrease with the maintenance time due to their passivation in solution. The microscopic analysis of the alloy surfaces shows that this passivation in solution does not modify the corrosion type. The alloys with PREN <or=32.9 are susceptible of localized corrosion.
对五种非贵金属镍钴基合金的腐蚀行为进行了分析。在合金钢中，元素铬、钼、钒的含量与用点蚀抗力当量数（PREN）指数表示的腐蚀行为之间的相关性，被扩展用于镍铬和钴铬牙科合金的表征。通过线性极化曲线和循环极化曲线，评估了五种镍铬或钴铬合金在Afnor型人工唾液中的开路电位、作为腐蚀速率度量的腐蚀电流密度以及腐蚀过程的主要参数。合金在腐蚀介质中的保持时间会影响腐蚀速率；由于它们在溶液中钝化，腐蚀电流值会随着保持时间的延长而降低。合金表面的微观分析表明，这种在溶液中的钝化不会改变腐蚀类型。PREN≤32.9的合金易发生局部腐蚀。
