【作者】 王宇航；

【导师】 汤宝寅；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2007， 博士

【摘要】 随着现代工业、高新技术的发展,传统的单一表面改性技术已不能适应恶劣条件、复杂物理环境下的工程应用,所以需要对已有的表面改性技术进行优化设计和组合,从特殊的应用背景出发,将两种或多种材料表面改性技术组合成复合处理技术,使材料表面获得单种表面改性技术无法得到的新的表面特性,从而满足新的工程应用的需要。特别是在航空航天领域,零部件减重带来的轻质钛铝合金的广泛应用以及磨损现象的普遍存在,迫切要求提高钛铝合金的表面性能,特别是轻质承载部件的耐磨损性能。本课题希望通过对PIII&D表面复合强化处理技术的研究,推动表面复合强化处理技术的发展,并为航空航天领域轻质承载部件耐磨损性能的提高提供可行的技术措施。本课题采用PIII&D方法对不同硬度的GCr15、Ti6Al4V、LY12基体进行了表面强化处理,并对不同表面强化处理后样品的耐磨损性能进行了研究。进一步采用有限元模拟压痕试验的方法,通过分析承载条件下膜基体系的应力应变分布研究了不同膜基体系的静态承载能力。研究发现对于硬基体材料如GCr15基体的PIII&D表面复合强化处理,由于C离子注入膜层薄且与表面DLC膜层的性能相近,复合强化处理对于体系的静态承载能力没有很大的影响。但PIII&D表面复合强化处理可以显著的提高硬基体材料的耐磨损性能,对于GCr15基体,经过复合强化处理后体系的磨损寿命比表面沉积DLC单层膜的体系提高了5倍以上。耐磨损性能的提高主要是由于C离子注入提高了膜基界面处的结合能力,并降低了界面残余应力的结果。对于软基体材料,如Ti6Al4V钛合金和LY12铝合金基体,采用PIII&D表面复合强化处理技术可以显著提高体系的静态承载能力,主要是因为中间过渡层的加入可以降低承载条件下界面处的应力,降低了发生塑性变形的可能。TiN/Ti(CN)x/TiC结构的中间过渡层形成的弹塑性性能梯度结构具有最好的承载效果,提高中间过渡层的厚度可以进一步提高膜基体系的承载能力。由于铝合金基体材料的硬度更低,中间过渡层对承载能力的作用更为明显。对于软基体材料,体系的承载能力是影响耐磨损性能的关键,采用PIII&D方法制备的TiN/Ti(CN)x/TiC/DLC多层膜结构,不但可以提高体系的承载能力,而且形成的梯度过渡还可以降低界面处的残余应力,显著提高了体系的耐磨损性能。对于Ti6Al4V基体,经过复合强化处理后体系的磨损寿命比表面沉积DLC单层膜的体系提高了10倍以上,而且中间过渡层厚度的增加可以进一步提高体系在重载条件下的耐磨损性能,具有2.25μm厚度中间过渡层的体系在1GPa载荷作用下,寿命达到了60000转以上。对于铝合金LY12基体,采用PIII&D复合强化处理技术在表面形成了Ti/TiN/Ti(CN)x/TiC/DLC的多层梯度膜结构,显著提高了膜基体系的承载能力和耐磨损性能。通过对不同基体表面PIII&D复合强化处理改性层性能的研究,本课题总结了PIII&D表面复合强化处理耐磨损层的膜层设计的原则。根据基体性能和服役条件,将基体材料分为软基体材料和硬基体材料两类,并分别给出了相应的PIII&D复合强化处理工艺过程。更多还原

【Abstract】 With the development of modern industry and new technology, the traditional surface modification techniques haven’t met the requests of application under serious conditions. Therefore, two or more surface modification techniques need to be involved to produce a duplex treatment technique to meet the new requests of application, which are unobtainable through any individual surface modification technique. Especially in the field of avigation and aeronautics, it is exigent to improve the surface properties of components under wear, because the titanium and aluminium alloys are widely used to reduce the weight of industrial components. By this study, the author hope that the investigation can promote the development of duplex technology and offer effective technical methods to improve the wear resistance of soft alloy components. In this paper, PIII&D duplex treatments were conducted on the GCr15, Ti6Al4V and LY12 substrates, and the wear resistance of samples was investigated. Moreover, the load bearing capacity of coating-substrate systems was investigated by FE analysis of the indentation test to analyze the distribution of stress and strain in the coating-substrate system.The results show that the duplex treatment of GCr15 have a less effect on the load bearing capacity of system because of the thin film and structure like DLC coating by C ion implantation. The wear resistance of system can be drastically improved by PIII&D duplex treatment, and the wear life of sample by duplex treatment was increased by 5 times compared with the single DLC layer. The improvement of wear resistance is attributed to the increase of interface adhesion and decrease of residual stress.The load bearing capacity can be enormously improved by PIII&D duplex treatment for Ti6Al4V and LY12 substrates, mainly because that the transfer layer can decrease the stress and strain at the interface. The transfer layer of TiN/Ti(CN)x/TiC has the best effect for the gradient structure of elastic and plastic properties. The increase of thickness of transfer layer can also improve the load bearing capacity. For LY12, the increase of load bearing capacity is more obvious due to the softer substrate. The load bearing capacity has an important influence on the wear resistance of system. The transfer layer of TiN/Ti(CN)x/TiC by PIII&D can enormously improve the wear resistance of system not only due to the increase of load bearing capacity but also the decrease of residual stress at the interface. For Ti6Al4V substrate, the wear life of sample by duplex treatment was increased by 5 times compared with single DLC layer. The increase of thickness of transfer layer can also improve the wear resistance of system under high load, and the wear life of the sample with the 2.25μm transfer layer can be more than 60000 cycles under the load of 1 GPa. For LY12 substrate, the Ti/TiN/Ti(CN)x/TiC/DLC multi-layer gradient structure can enormously improve the load bearing capacity and wear resistance.In this paper, the coating design rules of PIII&D duplex treatment were concluded by the investigation of property. On the basis of substrate property and service condition, the substrate can be divided into soft substrate and hard substrate, and the corresponding PIII&D duplex treatments were offered.更多还原