Design of Nanocomposite Low‐Friction Coatings
Design of Nanocomposite Low‐Friction Coatings
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DOI：
10.1002/adfm.200600724
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发表时间：
2007-07
影响因子：
19
通讯作者：
O. Wilhelmsson;M. Råsander;Mattias Carlsson;E. Lewin;B. Sanyal;U. Wiklund;O. Eriksson;U. Jansson
中科院分区：
文献类型：
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作者：
O. Wilhelmsson;M. Råsander;Mattias Carlsson;E. Lewin;B. Sanyal;U. Wiklund;O. Eriksson;U. Jansson
运动表面之间的摩擦磨损是不可避免的，也是机械零件失效的重要原因。耐磨和低摩擦涂层可以延长工程部件的使用寿命。在这里，我们展示了一种设计低摩擦纳米复合碳化物涂层的新概念，该涂层具有形成无定形碳(C-C键)的内在驱动力。Ti-Al-C已被选为模型体系，但其思想是普遍的，应该适用于广泛的材料类别。本质上形成无定形碳的能力是通过将形成弱碳化物的金属(Al)置换成热力学稳定的单碳化物(TiC)的固溶体来实现的。这以可控的方式产生了嵌入在无定形碳基质中的碳化物颗粒的相分离的驱动力。在摩擦学接触中，无定形碳可以进一步石墨化，从而降低摩擦系数。因此，该模型系统具有自润滑机制，同时两相的比例可调，这为设计耐磨性和韧性提供了极好的可能性。结果表明，在不严重损失力学性能的前提下，含铝TiC涂层的摩擦系数可降低50%以上。
Friction and wear between moving surfaces is unavoidable and is an important reason for failure of mechanical components. A wear‐resistant and low‐friction coating can prolong the lifetime of an engineered component. Here we demonstrate a new concept for the design of low‐friction nanocomposite carbide coatings with an intrinsic driving force to form amorphous carbon (C–C bonds). Ti–Al–C has been chosen as a model system, but the idea is general and should be applicable to a wide class of materials. The ability to intrinsically form amorphous carbon is achieved by a substitutional solid solution of the weak‐carbide‐forming metal (Al) into the thermodynamically stable monocarbide (TiC). This creates, in a controllable manner, a driving force for phase separation of carbide particles embedded in a matrix of amorphous carbon. In a tribological contact the amorphous carbon can be further graphitized and thereby lower the friction coefficient. Consequently, the model system has a self‐lubricating mechanism but at the same time a tunable share of the two phases, which gives excellent possibilities to design wear resistance and toughness. In this paper we show that the friction coefficient can be lowered by more than 50 % for Al‐containing TiC coatings without severe loss in mechanical characteristics.