载流摩擦磨损过程中材料磨损表面形貌与电弧相互作用关系的研究

发布时间：2019-03-17 17:45

【摘要】：载流摩擦磨损过程中,摩损表面形貌不断发生变化,会影响电弧放电,而电弧反过来又会影响表面形貌,探究两者的相互作用关系,以进一步了解电弧行为与载流摩擦磨损性能的动态变化。为此,在HST-100高速载流摩擦磨损试验机上以铜/铬青铜为摩擦副进行载流摩擦磨损试验。结合摩擦系数、磨损率的变化,探究电弧与载流摩擦磨损性能的关系;利用扫描电子显微镜(SEM)和能谱仪(EDS)对摩擦表面以及纵剖面进行微观观察,分析磨损表面形貌的变化特点;利用三维形貌仪测量磨损表面粗糙度,对表面形貌、电弧参数以及载流摩擦磨损性能参数进行定量分析,探究表面粗糙度与电弧能量、载流摩擦质量和载流摩擦磨损性能之间的相互作用关系。研究结果表明,载流摩擦过程中,摩擦表面上有显著的粘着磨损现象,并形成层片状磨屑与棒状磨屑。摩擦表层及次表层存在塑性变形区且随着距离摩擦表面远近的不同,变形区形貌也不同。摩擦时间短的塑性变形区较窄且分层不明显;随着摩擦时间增加,塑性变形区变大且分层明显;磨损后期,材料熔融堆积严重,严重塑性变形区较大,而整体变形区有所减小。对于纯铜材料而言,电弧侵蚀形式主要有熔融喷溅与熔融堆积。在载流摩擦过程中,纯铜摩擦表面发生了氧化。载流摩擦磨损过程中,不同磨损时期,表面粗糙度与电弧参数、载流质量、载流摩擦磨损性能的变化不同,而且相互作用,相互影响。质量磨损率呈“U”形变化,材料的磨损率与电弧的强度成正比例非线性关系。磨损初期,表面粗糙度较大,起弧频率较高且多为大电弧,相应的电弧能量也较高,质量磨损率较大;磨损中期,表面粗糙度较低,起弧频率以及大电弧出现频率均较小,电弧能量小,摩擦系数与质量磨损率较低,摩擦副接触状态较好,整体载流摩擦磨损性能好;磨损后期,表面质量变差,摩擦系数升高,电弧能量升高,磨损率增加,摩擦状态变差。
[Abstract]:In the process of current-carrying friction and wear, the surface morphology changes constantly, which will affect the arc discharge, and the arc in turn will affect the surface morphology, to explore the interaction between the two. In order to further understand the arc behavior and the dynamic change of current-carrying friction and wear properties. Therefore, the current-carrying friction and wear tests were carried out on the HST-100 high-speed current-carrying friction and wear tester using copper / chromium bronze as friction pair. According to the change of friction coefficient and wear rate, the relationship between arc and current-carrying friction and wear properties is discussed. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to observe the friction surface and longitudinal profile, and the change characteristics of the worn surface morphology were analyzed. The surface roughness, arc parameters and current-carrying friction and wear performance parameters were quantitatively analyzed by using a three-dimensional topography instrument, and the surface roughness and arc energy were investigated. The interaction between current-carrying friction quality and current-carrying friction and wear properties. The results show that there are obvious adhesion and wear phenomena on the friction surface in the process of current-carrying friction, and the lamellar wear debris and rod-like wear debris are formed. There is a plastic deformation zone between the friction surface and the subsurface, and the morphologies of the deformation zone are different with the distance from the friction surface to the friction surface. The plastic deformation zone with short friction time is narrow and the stratification is not obvious; with the increase of friction time, the plastic deformation zone becomes larger and more obvious; at the later stage of wear, the melt accumulation of the material is serious, the serious plastic deformation zone is larger, but the whole deformation zone is decreased. For pure copper materials, the main forms of arc erosion are melting spatter and melting accumulation. In the process of current-carrying friction, oxidation occurs on the friction surface of pure copper. In the process of current-carrying friction and wear, the surface roughness, arc parameters, current-carrying quality and friction and wear properties of the current-carrying friction and wear process are different from each other in different wear periods, and they interact and interact with each other. The wear rate of the material is changed in the shape of "U", and the wear rate of the material is non-linear in proportion to the strength of the arc. In the early stage of wear, the surface roughness is larger, the frequency of arc initiation is higher and the arc is large, the corresponding arc energy is also higher, and the wear rate of mass is higher. In the middle stage of wear, the surface roughness is low, the frequency of arc initiation and the occurrence frequency of large arc are lower, the energy of arc is small, the friction coefficient and mass wear rate is lower, the contact state of friction pair is better, and the overall current carrying friction and wear performance is good. At the end of wear, the surface quality, friction coefficient, arc energy, wear rate and friction state become worse.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.58

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