【作者】 谭宏斌；

【导师】 刘道新；

【作者基本信息】 西北工业大学 ， 材料学， 2007， 硕士

【摘要】 微动疲劳(Pretting fatigue，简称FF)是钛合金压气机叶片榫头的重要失效形式，由此影响发动机的安全可靠性。然而，由于FF过程的复杂性和影响因素颇多，因此，目前尚无十分有效的控制钛合金叶片高温FF的措施。表面改性与涂层技术是控制FF损伤十分有前景的技术途径之一。本文针对钛合金高温FF损伤控制的难题，采用离子束辅助沉积技术在钛合金表面制作耐磨层，研究膜层制备工艺，并对膜层的基本性能和摩擦学行为进行评价。在此基础上，探讨离子束辅助沉积膜层及其与喷丸形变强化(SP)复合处理对钛合金高温FF行为的影响规律和机制，拟为钛合金高温FF损伤控制的新途径提供依据。主要研究工作和取得的研究结论如下： (1) 研究了离子束辅助沉积TiN/Ti、0Cr18Ni9、NiCr20、A1膜层工艺，获得了膜基结合强度高、膜层致密性好、膜层强韧性优的TiN/Ti、0Cr18Ni9、NiCr20膜层，以及具有良好减摩润滑作用的A1软质膜层。硬质膜层TiN/Ti既具有良好的减摩效果，同时也有很高的抗磨作用，使钛合金基材耐磨性能显著提高。0Cr18Ni9和NiCr20膜层硬度明显高于整体材料，虽无减摩效果，但对钛合金基材耐磨性能有一定的提高。 (2) 研究了离子束辅助沉积TiN/Ti、0Cr18Ni9、NiCr20、A1膜层对Ti811钛合金FF性能的影响。发现硬质膜层TiN/Ti显著提高了钛合金350℃温度下的微动疲劳寿命，原因是该膜层有足够高的强韧性和Ti颗粒在高温下的减摩润滑性能；减摩润滑作用显著的软质A1膜层也大幅度地提高钛合金的FF寿命。0Cr18Ni9和NiCr20膜层则对Ti811钛合金FF性能无显著影响。 (3) 研究了喷丸强化与离子束辅助沉积TiN/Ti、0Cr18Ni9、NiCr20膜层复合处理(SP在先)对钛合金FF行为的影响。结果表明，复合处理试样的FF寿命虽然均高于BM状态的试样，但是却未实现联合提高钛合金FF抗力的目的，主要原因是，先喷丸强化处理，后进行离子束增强沉积膜层，后处理显著降低了SP引入的表面残余压应力，并且突显了SP表面损伤的不利因素；同时，SP表面处理对膜层的结合强度、韧性、膜基变形协调能力等产生了不利影响。更多还原

【Abstract】 Fretting fatigue (abbreviated as FF) is an important failure way of Compressor Blade Tenon made from titanium alloy, thus it affects reliability of engine. However, there are no effective measures to slove the FF problem of titanium alloy blade at high temperature now, for its complication and so many influencing factors. Coating and surface modification technology is very promising technology approaching fretting fatigue. To slove the FF problem of titanium alloy at high temperature, the ion-beam assisted deposition (IBAD) technology was applied to prepare the anti-wear coating on the surface of titanium alloy, and the process of coating, the evaluation of coating basic property and tribology behavior were also investigated. On the basis of aboved work, the influencing principles of ion beam assisted deposition coating and duplex treatment coating which combines shot peening (SP) with IBAD technology were studied, and their mechanism was investigated to provide guide to new ways of controling FF damage of titanium alloy at high temperature. The main contributions are as follows:(1) On the basis of optimizeing processes, the excellent adhesive strength, denser and tenacious coatings (including IBAD TiN/Ti, IBAD 0Cr18Ni9, IBAD NiCr20 andIBAD Al) were prepared, while the soft Al coating with good lubrication and outstanding anti-friction property was also acquired. The hard TiN coating with good wear resistance significantly improve wear property of titanium alloy.The hardness of 0Cr18Ni9 and NiCr20 coatings are significantly higher than bar material, and they have a certain improvement in the wear resistance of titanium alloy, although they can’t reduce coefficient of friction.(2) The effect of IBAD coatings which include TiN/Ti, 0Cr18Ni9, NiCr20 and Al on the FF behavior of titanium alloy were studied. It was founded that the hard TiN/Ti coating significantly improves fretting fatigue life of titanium alloy at 350℃, because of the good tenacity of coating and excellent lubrication of Ti partiles.The soft Al coating with good tribology and lubrication has greatly prolonged the FF life of itanium alloy. NiCr20 and 0Cr18Ni9 coatings have no obvious effect on the FF of titanium alloy at elevated temperature.(3) The effect of the duplex treatment technology which combines SP with IBAD更多还原