The corrosion-wear behaviour of thermally oxidised CP-Ti and Ti-6Al-4V
The corrosion-wear behaviour of thermally oxidised CP-Ti and Ti-6Al-4V
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DOI：
10.1016/s0043-1648(03)00557-x
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发表时间：
2004-03-01
期刊：
影响因子：
5
通讯作者：
Çimenoglu, H
中科院分区：
文献类型：
--
作者：
Dearnley, PA;Dahm, KL;Çimenoglu, H
工业纯钛(Cp-Ti)和Ti-6Al-4V合金在生物医用植入物中的应用一直受到限制，因为它们对表面降解过程的抵抗力很差。本文比较了未处理和热氧化处理的Cp-Ti和Ti-6Al-4V的腐蚀磨损性能。两种合金在625℃下氧化3~6小时，形成一层硬度接近1000HV的二氧化钛(金红石)外层。在室温下，用浸泡在生理盐水(0.89%氯化钠)中的α-Al_2O_3球进行往复滑动接触腐蚀磨损试验。氧化处理延缓了未处理的Cp-Ti和Ti-6Al-4V合金的腐蚀磨损，表面损伤以微细粗糙度剪切为主，磨损迅速。氧化材料的腐蚀磨损较慢，但更为复杂。氧化后的Ti-6Al-4V合金表面形成的TiO2层几乎没有起到保护作用，在试验的前60分钟内，它通过界面断裂的过程迅速被去除。相反，TiO2层虽然较薄，但为氧化的Cp-Ti提供了保护。这里，通过被认为是由二氧化钛层的机械解离引起的过程，该层变得平滑磨损。对于这两种氧化钛合金，在TiO2层下面形成了硬化氧扩散区(ODZ)。提供良好的防腐蚀磨损保护。在这两种情况下，ODZ都是通过磨损和腐蚀磨损过程相结合而顺利磨损的。后一种过程称为I型腐蚀磨损，涉及通过水腐蚀形成的钝化膜的重复机械降解。然而，这是一个相对缓慢的过程。(C)2003爱思唯尔B.V.保留所有权利。
The use of commercial purity titanium (CP-Ti) and Ti-6Al-4V alloys in bio-medical implant applications has been limited by their poor resistance to surface degradation processes. In this paper the corrosion-wear behaviour of untreated and thermally oxidised CP-Ti and Ti-6Al-4V have been compared. Oxidation of both alloys at 625degreesC for 3 6 h resulted in the formation of an exterior layer of TiO2 (rutile) that had a hardness similar to1000 HV. Corrosion-wear tests were made in reciprocation sliding contact with an alpha-Al2O3 ball immersed in physiological saline (0.89% NaCl) at room temperature. The oxidation treatment retarded the corrosion-wear of both CP-Ti and Ti-6Al-4V For the untreated alloys, surface damage was dominated by micro-asperity shearing which resulted in rapid wear. Corrosion-wear of the oxidised materials was slower but more complex. The exterior TiO2 layer formed on the oxidised Ti-6Al-4V alloy provided little protection, it was rapidly removed during the first 60 min of testing, by a process involving interfacial fracture. Conversely, the TiO2 layer, albeit thinner, provided protection for the oxidised CP-Ti. Here, the layer becomes smoothly worn by a process that is proposed to be caused by the mechanical dissociation of the TiO2-layer. For both oxidised titanium alloys the hardened oxygen diffusion zone (ODZ), formed beneath the TiO2 layer. provided good protection from corrosion-wear. In both cases the ODZ was smoothly worn by a combination of abrasion and corrosion-wear processes. The latter process, termed Type I corrosion-wear, involves the repetitive mechanical degradation of the passive film that forms through aqueous corrosion. However, this is a relatively slow process. (C) 2003 Elsevier B.V. All rights reserved.