形态耦元及特征量对灰铸铁油润滑磨损性能的影响

发布时间：2018-04-01 02:20

本文选题：滑动导轨　切入点：仿生耦合　出处：《吉林大学》2015年硕士论文

【摘要】：机床作为机械加工工业的基础生产设备，是可以自己制造自己的机器，被称为工作母机，在工业生产中占有举足轻重的地位。而机床导轨作为机床的重要部件，一直以来都是机床生产中十分重要的关键性技术问题，机床导轨直接影响着机床整体的加工质量，比如生产率，加工精度与机床寿命等。铸铁材料的减振与稳定性良好，稳定性强且成本相对低廉，所以是大部分机床导轨的首选材料，其中灰铸铁在滑动导轨中被广泛使用。导轨的主要失效形式是磨损，因此在影响导轨精度的因素中磨损是主要影响因素。机床滑动导轨的磨损形式主要有磨粒磨损和咬合磨损两种形式，因此其磨损率较高。在铸铁—铸铁的导轨副中，如果两者均没有淬火，在完全没有润滑油或润滑油不足的情况下，磨损将非常严重，局部压力非常高或者存在机械杂质时更加严重。近些年机械行业飞速发展，机床作为机械行业乃至工业加工生产中不可或缺的组成部分，也要跟上时代的步伐，做到精益求精，所以提高机床使用寿命也是一个亟待改善的问题。仿生学是一门在模仿生物体原型基础上，为了获取某些性能从而依据模型进行改进的一门综合性较强的新兴学科。根据仿生耦合原理建立形态与材料耦合的耦元仿生模型，目的在于提高其受力均匀性与协调性。并利用激光熔敷技术对材料表面进行局部加工，使耦合表面温度升高，达到相变温度，进而组织发生了改变，相变后的表面组织更加致密，同时硬度增强，从而实现了耐磨性的提高。这种方法成本低廉，安全可靠，所以受到了机床生产者与使用者的喜欢与青睐。针对滑动机床导轨灰铸铁材料硬度不足，耐磨性差的弱点，本文根据仿生耦合理论，以植物的叶片与贝壳作为抗磨损生物原型，结合生产实际优化设计了条纹状与点状仿生耦合单元体模型，并利用激光熔凝技术在导轨灰铸铁材料上进行相应的耦合模型加工。为了提高机床导轨的耐磨性，通过改变单元体形状、单元体间距、磨损角度等指标，进行油润滑试验，来寻求最佳的仿生耦元设计模型。通过实验数据与理论研究，得到的结论为：油润滑条件下仿生耦合试样的耐磨损性能与未处理试样比有了明显提高，单元体的形态、分布间距、排布角度对仿生耦合试样的油润滑磨损性能影响显著，其中网状耦合试样的耐磨性较好；而磨损角度一定时，单元体间距减小时，仿生耦合试样的耐磨性越好，但全熔凝试件没有单元体间距为1mm试样耐磨性好；而单元体间距一定时，磨损角在45°时的试样耐磨性最好。其本质是改变了试样表面的单元体所占面积比例，且所占面积比例越大，，油润滑条件的耐磨损性能越好,当然全熔凝试件由于没有缓冲作用,不利于油膜形成,耐磨性不如间距1mm试件。这些实验结果为以后机床导轨的设计与生产提供了理论参考依据，具有一定的指导意义。
[Abstract]:Machine tool, as the basic production equipment of mechanical processing industry, can make its own machine, which is called working mother machine, and plays an important role in industrial production.As an important part of machine tool, the guide rail of machine tool has always been a very important key technical problem in machine tool production. The guide rail of machine tool directly affects the machining quality of machine tool, such as productivity, machining precision and machine tool life.Because of its good vibration absorption and stability, strong stability and relatively low cost, cast iron is the preferred material for most machine tool guideways, among which gray cast iron is widely used in sliding guideways.Wear is the main failure form of guide rail, so wear is the main factor affecting the precision of guide rail.There are two kinds of wear forms of machine tool sliding guide rail: abrasive wear and bite wear, so the wear rate is higher.In the cast iron-cast iron guideway pair, if neither is quenched, the wear will be very serious when there is no lubricating oil or insufficient lubricating oil at all, and the local pressure will be very high or even more serious in the presence of mechanical impurities.With the rapid development of machinery industry in recent years, machine tools, as an indispensable part of machinery industry and even industrial processing and production, should also keep up with the pace of the times and strive for perfection.Therefore, it is an urgent problem to improve the service life of machine tools.Bionics is a new and comprehensive subject which is based on the prototype of imitating organisms and improves according to the model in order to obtain some properties.According to the principle of bionic coupling, a coupling element bionic model is established, which aims to improve the uniformity and coordination of the force.The laser cladding technology is used to locally process the surface of the material, which makes the coupled surface temperature rise and reach the phase transition temperature, and then the microstructure changes, the surface structure after phase transformation becomes denser and the hardness increases.Thus, the wear resistance is improved.This method is low cost, safe and reliable, so it is liked and favored by machine tool producers and users.In this paper, according to the bionic coupling theory, the blade and shell of the plant are used as the anti-wear biological prototype, in view of the weakness of the gray cast iron material of sliding machine tool guideway, which is short of hardness and poor wear resistance, according to the bionic coupling theory.In this paper, the bionic coupling unit model of stripe and dot is designed in combination with the practical production, and the coupling model is processed on the guide gray cast iron material by laser melting technology.In order to improve the wear resistance of the guide rail of the machine tool, oil lubrication tests were carried out to find the best design model of the bionic coupling element by changing the shape of the unit body, the spacing of the unit body, the wear angle, and so on.Based on the experimental data and theoretical study, the results are as follows: the wear resistance of the bionic coupling sample under oil lubrication is obviously improved compared with the untreated sample, and the shape and distribution distance of the unit body are obtained.The distribution angle has a significant effect on the oil lubricating and wear properties of the bionic coupling sample, and the better the wear resistance of the coupling sample is, the better the wear resistance of the bionic coupling specimen is when the wear angle is fixed.However, the wear resistance of the 1mm specimen is better than that of the 1mm specimen, and the wear resistance of the specimen with 45 掳wear angle is the best when the unit body spacing is constant.Its essence is to change the area proportion of the unit body on the surface of the sample, and the larger the area proportion is, the better the wear resistance of the oil lubricating condition is, of course, because the total melt solidification specimen has no buffering effect, it is not conducive to the formation of oil film.Wear resistance is not as good as spaced 1mm specimens.These experimental results provide a theoretical basis for the design and production of machine tool guideways.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG502.16

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