外源第三体对材料摩擦性能的影响

发布时间：2018-05-15 05:14

本文选题：摩擦 + 粉末　；参考：《大连交通大学》2012年硕士论文

【摘要】：随着列车速度的提高，制动系统承受着巨大的载荷和动量，摩擦制动的稳定性问题日益突出，探讨影响摩擦性能的因素成为提高列车安全运行的一个重要问题。其中，在摩擦表面形成的第三体是影响材料摩擦性能的一个重要因素。因此，系统地研究摩擦面第三体对摩擦材料摩擦性能的影响机理，澄清每种组元在摩擦面上产生第三体的作用机制，就成为研发高性能摩擦材料的基础性问题。本文利用GF150D定速摩擦机，以Q235钢和H13钢为摩擦副，通过外加铜粉、铁粉、铝粉、SiO2的方式，并研究了摩擦顺序、摩擦压力、摩擦速度对材料摩擦性能的影响，结果表明：添加铜粉条件下，摩擦系数增加，摩擦系数的增加程度与添加方法有关，孔式添加法可使摩擦系数增加0.2以上，，而外洒法添加使摩擦系数增加0.1~0.2左右，原因在于孔式添加法的添加量大于外洒法，稳定充足的第三体铜粉的变形和黏性流动增加了摩擦面上的啮合程度，起到增加摩擦力的作用。添加铝粉后，摩擦系数增加0.1左右，添加方法对摩擦系数的影响不明显。随摩擦速度增加，摩擦系数降低，低速下，干摩擦系数高于湿摩擦系数，而高速下则相反。铝粉对摩擦系数影响程度小于铜粉的原因在于铝粉的氧化物硬度高、变形程度差，不利于增加摩擦面的啮合程度。添加铁粉后，低速下，摩擦系数变化不明显，当速度超过1500r/min后，材料的摩擦系数提高0.1左右，其原因在于铁粉的性质与摩擦副表面的性质基本相同，其原因在于铁粉的性质与摩擦副表面的性质基本相同，高速条件下由于氧化加剧而相当于增加了第三体的氧化物含量导致摩擦系数有所增加。添加SiO2后，摩擦系数变化不明显。由于SiO2是脆性氧化物，细小的SiO2颗粒在表面可同时产生滚动作用和犁沟效应，这两种作用相互抵消，导致材料的摩擦系数变化不大。
[Abstract]:With the increase of train speed, the braking system bears a huge load and momentum, and the stability of friction braking is becoming more and more serious. It is an important problem to discuss the factors that affect the friction performance of the train. Among them, the third body formed on the friction surface is an important factor affecting the friction properties of the material. Therefore, it is a basic problem to study the influence mechanism of the third body of friction surface on the friction performance of friction material, and to clarify the mechanism of the third body on the friction surface of each component in the research and development of high performance friction material. In this paper, the effects of friction sequence, friction pressure and friction speed on the friction properties of the material are studied by using GF150D constant speed friction machine, using Q235 steel and H13 steel as friction pairs and by adding copper powder, iron powder and aluminum powder to SiO2. The results show that the friction order, friction pressure and friction speed affect the friction properties of the material. Under the condition of adding copper powder, the friction coefficient increases, and the increase degree of friction coefficient is related to the adding method. The friction coefficient can be increased more than 0.2 by the hole type addition method, but by adding the external sprinkling method, the friction coefficient can be increased by about 0.1% 0.2. The reason lies in the fact that the addition amount of the hole type addition method is larger than that of the external sprinkling method, and the stable and sufficient deformation and viscous flow of the third body copper powder increase the meshing degree on the friction surface and play the role of increasing the friction force. After adding aluminum powder, the friction coefficient increased about 0.1, but the effect of adding method on friction coefficient was not obvious. With the increase of friction speed, the friction coefficient decreases. At low speed, the dry friction coefficient is higher than the wet friction coefficient, but at high speed it is opposite. The reason that the influence of aluminum powder on friction coefficient is lower than that of copper powder is that the oxide hardness of aluminum powder is high, and the degree of deformation is poor, which is not conducive to increasing the meshing degree of friction surface. After adding iron powder, the friction coefficient does not change obviously at low speed. When the speed exceeds 1500r/min, the friction coefficient of the material increases about 0. 1. The reason is that the properties of iron powder are basically the same as those of the surface of friction pair. The reason lies in the fact that the properties of iron powder are basically the same as those of the surface of the friction pair, and the friction coefficient is increased at high speed due to the increase of oxide content of the third body due to the increase of oxidation at high speed. When SiO2 was added, the friction coefficient did not change obviously. Due to the fact that SiO2 is a brittle oxide, the fine SiO2 particles can produce both rolling and ploughing effects on the surface, which counteract each other, resulting in little change in the friction coefficient of the material.
【学位授予单位】：大连交通大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH117.1

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