稀土改性玻璃纤维对PTFE复合材料摩擦磨损性能的影响

分别用硅烷偶联剂SG-Si900(SGS)、含SG-Si900的稀土溶液(SGS/RES)和稀土溶液(RES)对玻璃纤维进行表面改性,考察了稀土改性玻璃纤维填充的PTFE复合材料在油润滑条件下的摩擦磨损性能,并用扫描电子显微镜(SEM)分析了磨损表面形貌.结果表明:与未经表面改性玻璃纤维填充的PTFE复合材料相比,经表面改性玻璃纤维填充的PTFE复合材料的减摩耐磨性能得到提高,以RES的作用最明显,SGS/RES次之,SGS第三;在油润滑条件下,稀土改性玻璃纤维填充的PTFE复合材料只出现了轻微磨损,这是由于玻璃纤维经稀土表面改性后极大地改善了玻璃纤维与PTFE基体之间的界面结合力,使稀土改性玻璃纤维填充的PTFE复合材料具有优异的摩擦磨损性能.     

旋转吹氮铝液精炼方式的改进及效果研究

为了改善铝合金重力铸造中针孔及夹杂缺陷，通过对吹氮净化铝液工艺中的旋转喷头的改进，来细化氮气气泡的体积，增加氮气与铝液的接触面积，从而提高除气除渣的效果，达到铝液净化的目的，最终提高产品的质量。     

高温形变循环热处理对TiNi合金组织细化的影响

利用热机械模拟系统，对铸态Ti-50．3at％Ni合金进行高温形变循环热处理，研究不同热处理工艺对其组织细化的影响。结果表明：经过高温形变循环热处理，可以获得晶粒尺度在10μm以下的均匀单相显微组织。试样分别在55012和60012进行塑性变形，然后继续加热到80012短时保温进行不同的循环热处理，发现在55012变形后晶粒细化效果更加明显。还探讨了铸态Ti-50．3at％Ni合金高温形变循环热处理中组织的细化机理及其影响因素。     

PMC 1007型车丝机程序开发研究

介绍了PMC1007型车丝机的三工位加工原理，分析了该机长期役径后产品质量恶化的原因，提出了利用接近开关进行工位分离的方法，并对分离的夹具误差在加工程序中分别实现补偿，还给出了实现在屏幕程序中加入新工艺的四个主要模块。     

Effect of rare earths surface treatment on tribological properties of carbon fibers reinforced PTFE composite under oil-lubricated condition

The effect of rare earths （RE） surface treatment of carbon fibers （CF） on tribological properties of CF reinforced polytetrafluoroethylene （PTFE） composites under oil-lubricated condition was investigated. Experimental results revealed that RE treated CF reinforced PTFE （CF/PTFE） composite had the lowest friction coefficient and wear under various applied loads and sliding speeds compared with untreated and air-oxidated composites. X-ray photoelectron spectroscopy （XPS） study of carbon fiber surface showed that, after RE treatment, oxygen concentration increased obviously, and the amount of oxygen-containing groups on CF surfaces were largely increased. The increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, stress could be effectively transmitted to carbon fibers; carbon fibers were strongly bonded with VITE matrix, and large scale rubbing-off of PTFE be prevented, therefore, tribological properties of the composite was improved.     

小载荷下滑动往复摩擦测试平台的研制

描述了自行研制的小载荷下滑动往复摩擦测试平台的工作原理。所设计的测力传感器能同时测定正压力和摩擦力，其悬臂由一组相互垂直的平行弹性钢片组成，其解耦特性经有限元软件ANSYS得到证明。采用虚拟仪器技术在PC机上实现了力信号的采集、分析与显示。标定及实测使用表明，该测试平台具有较高的测量精度和分辨力，适合小载荷（mN）下材料的摩擦性能测试。     

分形理论在摩擦学研究中的应用

对近年国内外分形理论在摩擦学研究中应用的新进展作了综述,介绍了分形的概念以及分形维数的计算方法,讨论了包括磨损表面形貌分析,材料表界面分形研究和磨合磨损分形模型的建立等分形理论在摩擦学研究中的应用状况,并提出了当前相关研究中所遇到的问题,及今后分形理论在摩擦学研究中的发展方向。     

稀土处理玻璃纤维填充PTFE复合材料的滑动磨损性能

研究了不同玻璃纤维表面处理对PTFE复合材料在干摩擦条件下滑动磨损性能的影响,并借助扫描电子显微镜(SEM)分析了磨损机理。结果表明:在干摩擦条件下,经表面处理玻璃纤维填充的PTFE复合材料的摩擦系数和摩擦表面温度比未经处理玻璃纤维填充的PTFE复合材料的低,且减磨性能优于未经处理的;而稀土处理玻璃纤维填充的PTFE复合材料的摩擦系数和摩擦表面温度最低,减磨性能最好;未经处理玻璃纤维填充的PTFE复合材料和偶联剂处理玻璃纤维填充的PTFE复合材料都发生了剧烈的粘着转移;偶联剂与稀土处理玻璃纤维填充的PTFE复合材料的磨损机理主要是明显的磨粒磨损;稀土处理玻璃纤维填充PTFE复合材料的磨损形式主要是粘着转移和轻微的磨粒磨损。     

Preparation and Tribological Investigation of Rare Earth Nanofilm on Single-Crystal Silicon Substrate

The self-assembled silicon substrate. The resultant contact angle meter and atomic method was introduced to successfully obtain film was characterized by means of X-ray rare earth（RE） nanofilm on a single-crystal photoelectron spectroscopy （XPS）, ellipsometer, force microscopy （AFM）. The scratch experiment was performed for interfacial adhesion measurement of the RE film. The friction and wear behavior of RE nanofilm was examined on a DF-PM reciprocating friction and wear tester. The results indicate the RE nanofilm is of low coefficient of friction （COF） and high wear resistance. These desirable characteristics of RE nanofilm together with its nanometer thickness, strong bonding to the substrate and low surface energy make it a promising choice as a solid lubricant film in micro electromechanical system （MEMS） devices.     

Effect of Rare Earths on Tribological Properties of Carbon Fibers Reinforced PTFE Composites

Carbon fibers （CF） were surface treated with air-oxidation and rare earths （RE）, respectively. The effect of RE surface treatment on tensile strength and tribological properties of CF reinforced polytetrafluoroethylene （PTFE） composites was invest/gated. Experimental results revealed that RE was superior to air ox/dation in improving the tensile strength, elongation, and the tensile modulus of CF reinforced PTFE （CF/PTFE） composite. Compared to the untreated and air-oxidated CF/PTFE composite, the RE treated composite had the lowest friction coefficient and specific wear rate under a given applied load and reciprocating sliding frequency. The RE treatment effectively improved the interfacial adhesion between CF and PTFE. With strong interfacial coupling, the carbon fibers carried most of the load, and direct contact and adhesion between PTFE and the counterpart were reduced, accordingly the friction and wear properties of the composite were improved.