经热处理的蛇纹石粉体对金属磨损特性的影响

用X射线衍射仪分析了在550 ℃和900 ℃热处理的两种蛇纹石粉体的相结构变化,并研究了不同的分散剂对蛇纹石微细粉体在润滑油中的分散性.在MM-200型摩擦磨损试验机上进行摩擦磨损试验,使用的润滑油为基础油和分别含有2种经热处理的蛇纹石粉体的润滑油.借助扫描电子显微镜和能谱仪分析了在上述3种润滑油润滑下#45钢环的表面形貌和成分.结果表明:在900 ℃热处理后蛇纹石发生相变;用钛酸酯偶联剂进行表面修饰的蛇纹石粉体在润滑油中具有良好的分散性;润滑油中,2种经热处理的蛇纹石都可以在金属摩擦磨损表面形成保护膜.在摩擦过程中,两接触表面上的微凸部分对粉体的研磨作用使粉体粒子表面带有大量的悬挂键,同时接触的金属摩擦副也形成活化表面,从而使粉体颗粒吸附在金属表面.在载荷的作用下,蛇纹石粉体颗粒在磨损表面铺展形成自修复膜.     

超声机械法制备一种抗磨润滑添加剂的自修复效应

采用超声机械法制备纳米A l2O3、SiO2、MgO等颗粒并对其进行化学修饰,使其稳定地分散在基础油中,获得自修复纳米润滑添加剂MF。通过四球试验与止推圈试验考察摩擦学性能,试验结果表明:自修复纳米润滑添加剂具有良好的分散稳定性和自修复性。     

金属摩擦表面再生技术在推焦车减速机上的应用

介绍金属摩擦表面再生技术在推焦车减速机上的应用效果。对应用该技术前后的减速机进行了温度和振动测试,结果表明,经过金属摩擦表面再生技术处理后,达到了修复齿轮磨损、降低振动、降低温升、延长减速机维修周期和使用寿命的效果,对增产、增效起到良好作用。     

油酸修饰自修复添加剂在金属摩擦副表面成膜过程研究

采用油酸对蛇纹石粉体进行表面修饰,使用红外光谱仪(IR)和X射线衍射仪(XRD)分析了它对粉体的分散机理.使用MM200摩擦磨损试验机研究金属摩擦副在含有自修复添加剂的润滑油润滑下的成膜过程,借助SEM及EDAX测试分析自修复膜层的表面形貌及表面成分组成.结果表明,油酸可以很好的使粉体分散于润滑油中,其作用机理为油酸与粉体表面的羟基发生酯化反应.当摩擦磨损时间很短时摩擦副表面就可出现自修复膜层,但成膜过程和磨损过程同步进行,随着时间的增加,膜层的形成愈来愈稳定,直至覆盖整个金属磨损表面.其成膜机理为,在摩擦过程中,两接触表面上的微凸体对粉体的研磨作用使粉体粒子表面带有大量的悬挂键,同时接触的金属摩擦副也形成活化表面,从而使粉体颗粒吸附在金属表面.在载荷的作用下,粉体颗粒在磨损表面铺展形成自修复膜.     

基于仿生硬件的无线传感器网络节点自修复方法

针对现有无线传感器网络节点硬件固定,不能重新配置的问题,设计了一种全新的基于仿生硬件的无线传感器网络节点自修复方法,采用仿生硬件实现动态可重构无线传感器网络节点,以使节点能够自主地、动态地改变自身的结构和行为,在其部分硬件失效情况下进行节点的仿生自修复.该研究提出了相关节点的仿生自修复方法,研制了基于现场可编程阵列的仿...     

Ni60A/MoS_2复合涂层润滑膜的形成及自修复机理

通过考察等离子体喷涂Ni60A/MoS2复合润滑涂层的摩擦学特性,探讨了复合涂层中MoS2润滑膜的形成及自修复作用,讨论了影响MoS2润滑膜形成过程及其润滑和减摩抗磨性能的因素,进而建立了用于说明润滑膜形成及破坏过程的物理模型。结果表明:润滑涂层润滑膜的形成机理包括摩擦开始、MoS2析出表面、MoS2覆盖表面和MoS2表面膜形成等4个阶段.润滑涂层润滑膜的破损过程包括膜的厚度不断减小、裂纹的产生、裂纹的扩展和润滑膜的剥落4个阶段.同时,硬质颗粒刺入润滑膜并导致润滑膜擦伤,从而大幅降低润滑膜的寿命,其降幅接近一半.     

测试评定自修复效果方法的探讨

通过试验,考察了振动测试法、称重法、摩擦因数法和表面分析法对评定自修复添加剂自修复效果的适用性,探讨了这些方法各自的优缺点。结果表明:振动测试、摩擦因数测定法和称重法测试自修复效果是自修复过程微观机制的宏观体现,自修复止推环表面显微观测、EDX能谱分析和XPS能谱分析结果是自修复动态修复的微观体现;振动测试、摩擦因数测定法和称重法更能体现出自修复过程中的动态修复特征,振动测试、摩擦因数测定法测试自修复过程与自修复动态过程同步一致性较好;振动测试较其它测试评价方法具有更大的优越性,是一种应用前景较好的自修复效果测评方法。     

Study on Self-Repairing Performance of Mineral Powder Lubrication Oil Additive to Engine

By means of the engine shelf test, the gas escape amount of bent axle box was measured before and after adding hydroxyl silicate mineral powder lubrication oil additives, and discovered that gas escape amount after self-repaired is obviously smaller than before, the average gas escape amount of each rotate speed descend 6.5 %. Watching friction surface with SEM, discovered that the part of net veins in the cylinder inner surface are smoothly patched. Analysis with energy spectroscopy, discovered that there are some changing of atom component. Proofed that through rub chemical reaction, hydroxyl silicate mineral powder lubrication oil additives can generate new substance layer on friction surface, and can increase cylinder inner surface bulk, thereby get the repaired effects.     

Self-Repairing Mechanical Systems

This paper reviews several types of self-repairing systems developed in the Mechanical Engineering Laboratory. We have developed a modular system capable of self-assembly and self-repair. The former means a set of units can form a given shape of the system without outside help; the latter means the system restores the original shape if an arbitrary part of the system is cut off. We show both two-dimensional and three-dimensional unit designs, and distributed algorithms for the units.     

Direct self-repairing control for a helicopter via quantum multi-model and disturbance observer

In this paper, a new direct self-repairing control scheme is developed for a helicopter flight control system with unknown actuator faults and external disturbance. The design of multi-model-based adaptive control is used to accommodate the faulty system under different fault conditions. By appropriate switching based on quantum information technique, the system can be converted to the best model and the corresponding controller. Asymptotic model following performance and system stability is guaranteed. A disturbance observer is introduced to observe the disturbance of the system, which can produce corresponding control signals according to the disturbance. The results including a numerical simulation and a semi-physical verification demonstrate the effectiveness of the proposed self-repairing control approach for the helicopter flight control system.