表面改性硅灰石纤维填充PTFE复合材料的摩擦学性能

用KH550硅烷偶联剂表面改性的硅灰石纤维(WF)填充PTFE,在MPX-2000型磨损试验机上研究复合材料的摩擦磨损性能,并与经典的炭纤维(CF)填充PTFE复合材料进行比较。采用SEM对磨损面和对偶面进行分析。结果表明:较高载荷(200和300 N)下复合材料摩擦因数随WF含量变化的幅度不大,较稳定地维持在较低值;细小尺寸WF填充PTFE复合材料的耐磨性能较好,在WF质量分数为10%时,复合材料的磨损量只有相同含量CF填充PT-FE复合材料的81%;细小尺寸WF填充PTFE复合材料的磨损面较为平整,存在轻微黏着磨损,其对偶面转移膜平整光滑、结构致密;而CF/PTFE复合材料磨损面存在许多裸露和碎断的CF,犁削和磨粒磨损是主要的磨损形式。     

Microstructure and Wear Behaviors of Plasma-Sprayed FeCrNiMoCBSi Coating with Nano-Grain Dispersed Amorphous Phase in Reciprocating Sliding Contact

A novel FeCrNiMoCBSi amorphous/nanocrystalline coating was fabricated using a plasma spraying process. The coating was dense with a low porosity of approximately 0.99%. The coating consisted of a 67.8 vol% amorphous phase coupled with many nanocrystalline grains that were approximately 5?nm in diameter. The mechanical properties of the as-sprayed coating were determined by nanoindentation measurement, and the tribological behaviors were systematically investigated in a reciprocating sliding contact. The results show that FeCrNiMoCBSi coatings possess superior wear resistance compared to other typically similar Fe-based amorphous coatings. The tribological behaviors evolve with the combination of normal load and sliding velocity. Herein, the dominant wear mechanisms are delamination wear and oxidation wear. With an increase in normal load and sliding velocity, the abrasive wear is gradually weakened, the formation of oxide films on the worn surfaces is facilitated, and wear debris is ground to powder. The oxide films suffer from fatigue wear with induced cracks undergoing reciprocating sliding effects.     

表面织构化喷涂涂层摩擦学性能的模糊综合评判

运用等离子喷涂技术制备涂层,在涂层上采用激光表面微造型技术制备各种不同形貌的表面织构。对涂层进行不同温度、不同表面织构、不同润滑剂含量下摩擦磨损性能试验,然后运用模糊综合评判法建立涂层评价指标集,并采用三角模糊数矩阵确定各个指标权重,建立涂层性能模糊评价模型,对等离子喷涂涂层各个影响因素进行综合评判。结果表明：该方法获得的最佳涂层与基于BP神经网络得到的结果一致,它为评定涂层优异性能提供一种直观的量化方案。     

Protic Ionic Liquids with Ammonium Salts as Lubricants for Magnetic Thin Film Media

The newly synthesized perfluoropolyether (PFPE) whose terminal group is an ammonium salt with a carboxylic acid has better frictional and anti-corrosion properties when compared to the conventional PFPEs. The friction is almost independent of the PFPE structure, but depends on the amine structures. This modified PFPE uniformly covers the magnetic surfaces; this is why it not only reduces the friction, but also has an effect on the corrosion resistance.     

一种利用WC电极的电火花表面改性技术

研究了1种在普通电火花加工机床上实现金属工件表面改性的新方法。它是在传统电火花加工方法的基础上，采用WC烧结体电极和普通煤油工作液，在工件表面形成1层硬质陶瓷层，从而达到改善工件表面性能的目的。系统地对放电沉积原理进行了探讨，在大量试验的基础上，总结了放电沉积的工艺方法。通过扫描电镜、电子探针、X射线衍射分析、摩擦磨损等一系列试验手段，对形成的沉积层特性进行了定量和定性的分析。试验与分析表明，用电火花加工的方法进行表面处理是1种极具潜力的改性方法。