Subsurface microstructure of metal-on-metal hip joints and its relationship to wear particle generation
Subsurface microstructure of metal-on-metal hip joints and its relationship to wear particle generation
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DOI：
10.1002/jbm.b.30132
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发表时间：
2005-01-15
影响因子：
3.4
通讯作者：
Fischer, A
中科院分区：
文献类型：
--
作者：
Büscher, R;Täger, G;Fischer, A
为了控制和最大限度地减少金属对金属髋关节的磨损，了解碎片产生的机制至关重要。在体内，发现的主要是纳米级的球状和针状颗粒，这些颗粒既不是由于磨损作用，也不是由于摩擦化学反应。在这项研究中，代理磨损机制已首次确定的表面上通过扫描电子显微镜（SEM）。之后，使用透射电子显微镜（TEM）研究了外植体的亚表面区域的微观结构。观察的次表面提供了额外的洞察力的微观结构变化的钴基合金受到磨损。在一定距离的表面，一个网络的堆垛层错和六方是一个元素的马氏体被发现加强散装材料。这种微结构转变为纳米晶型移动接近表面。体内碎片尺寸和表面晶粒尺寸的比较表明，球状磨损颗粒是由撕裂的纳米晶体产生的，而针状颗粒是由断裂的E-马氏体产生的。通过纳米晶层传播的已识别裂纹进一步支持了这些发现。因此，它是建议，占主导地位的机制，颗粒产生的金属对金属接头内的纳米晶表面层的表面疲劳。(C)2004 Wiley Periodicals，Inc.
To control and minimize wear of metal-on-metal hip joints it is essential to understand the mechanisms of debris generation. In vivo, mainly nanosize globular and needle-shaped particles are found. These can neither stem from the action of abrasion nor from tribochemical reactions. In this study the acting wear mechanisms have been first identified on the surface by means of scanning electron microscopy (SEM). Afterwards, the microstructures of the subsurface regions of explants have been investigated using a transmission electron microscope (TEM). Observation of the subsurface gave additional insight about the microstructural changes of cobalt-base alloys subjected to wear. At some distance from the surface, a network of stacking faults and hexagonal is an element of-martensite was found strengthening the bulk material. This microstructure changed into a nanocrystalline type moving closer towards the surface. A comparison of in vivo debris size and grain size of the surface suggests that the globular wear particles result from torn off nanocrystals, while the needle shaped particles are generated by fractured E-martensite. Identified cracks, propagating through the nanocrystalline layer, further support these findings. Thus, it is suggested that the dominating mechanism of particle generation for metal-on-metal joints is surface fatigue within a nanocrystalline surface layer. (C) 2004 Wiley Periodicals, Inc.