磁场条件下W-20Cu复合材料的磨损行为及机理研究
发布时间：2018-11-17 14:27
【摘要】：随着电磁技术应用范围的扩大,越来越多的摩擦副材料在电磁工况环境下服役,如高速列车、电磁炮等,国内外对磁场环境下铁磁性材料的摩擦磨损性能研究较多,少见非铁磁性材料如W、Al、Ti、Cu等的研究。其中,钨铜材料在现代电子信息业和国防工业领域的应用日益扩大,因此探究其摩擦磨损性能及机理十分必要。本文选用W-20Cu分别与铁磁性材料45钢和顺磁性材料铝合金进行配副,采用改进的MPV-1500型销-环式摩擦磨损试验机,通过改变磁场强度、载荷和滑动速度来研究摩擦副的干摩擦特性;利用扫描电子显微镜(SEM)、X-ray衍射仪(XRD)、Nano-focus三维形貌仪和透射电子显微镜(TEM)等仪器对材料的摩擦面、纵切面及磨屑进行微观分析,探讨摩擦副的磨损机理,并通过模型图详细阐述钨铜复合材料的磨损过程。研究得到的主要结论如下:W-20Cu与45钢配副时,随着磁场强度的增加,钨铜销和45钢环的磨损率及配副的摩擦因数均呈降低趋势,说明磁场干涉下W-20Cu/45钢配副的耐磨性和减磨性得到改善。W-20Cu与铝合金配副时,随着磁场强度的增加,钨铜销的磨损率相对较小为负值,而铝合金环的磨损率逐渐增大,配副的摩擦因数先增大后趋于稳定,说明磁场加剧了W-20Cu/铝合金配副的磨损,其磨损机制主要为粘着磨损。W-20Cu与45钢配副时,随着磁场强度的增加,钨铜销的摩擦面趋于平滑,表面粗糙度降低了57.9%;施加磁场可降低钨铜摩擦纵切面的变形程度,变形层厚度由11.5μm降低到6.5μm,阻碍了裂纹的生成和扩展,减缓了磨屑的生成;磁场还可吸附磨屑并使之细化;此外,钨铜销摩擦面上出现铁磁性氧化物,说明磁场促进了氧化磨损,从而改善了配副的磨损性能。通过在不同载荷、滑动速度和磁场强度下对W-20Cu/45钢进行摩擦磨损试验研究表明,随着载荷的增加(80 N~320 N),配副的磨损率均增大而摩擦因数降低;摩擦面变得粗糙,平均氧含量降低,摩擦纵切面变形程度趋于严重,变形区厚度由5μm增大到43μm,磨损机制由轻微的磨粒磨损转变为严重磨损。随着滑动速度的增加,钨铜销的磨损率增大,环的磨损率降低,而配副的摩擦因数略微降低,钨铜摩擦面趋于平滑,犁沟变浅,且有局部脱落现象。无论载荷变还是速度变,与无磁场条件相比,磁场干涉下配副的摩擦因数和磨损率均相对较小。综合探讨了钨铜复合材料摩擦面及纵切面的组织结构变化及变形区裂纹的形成,并使用模型图详细阐述了钨铜复合材料销/45钢环配副的摩擦磨损过程。表明钨铜摩擦纵切面存在变形区,且变形区不同深度的位错结构等缺陷发生变化,越靠近钨铜摩擦面,钨晶粒内位错密度越高,甚至有大裂纹出现,且铜晶粒破碎越严重。
[Abstract]:With the expansion of the application of electromagnetic technology, more and more friction pair materials are in service under electromagnetic conditions, such as high-speed trains, electromagnetic guns and so on. The friction and wear properties of ferromagnetic materials under magnetic field environment are studied more and more at home and abroad. Rare non-ferromagnetic materials such as WCU Alu Tiu Cu and so on are studied. Among them, tungsten and copper materials are widely used in modern electronic information industry and national defense industry, so it is necessary to study their friction and wear properties and mechanism. In this paper, W-20Cu was used to match ferromagnetic material 45 steel and paramagnetic aluminum alloy respectively. The improved MPV-1500 type pin-ring friction and wear tester was used to change the magnetic field intensity. The dry friction characteristics of friction pairs are studied by loading and sliding speed. The wear mechanism of friction pairs was studied by means of scanning electron microscope (SEM), X-ray) (SEM), X-ray diffractometer (XRD), Nano-focus) and transmission electron microscope (TEM). The wear process of tungsten-copper composite is described in detail by model diagram. The main conclusions are as follows: with the increase of magnetic field intensity, the wear rate and friction coefficient of tungsten copper pin and 45 steel ring decrease with the increase of magnetic field intensity. The results show that the wear resistance and wear resistance of W-20Cu/45 steel pair are improved under magnetic field interference. With the increase of magnetic field intensity, the wear rate of tungsten and copper pin is negative when W-20Cu and aluminum alloy pair are matched. The wear rate of aluminum alloy ring increases gradually, and the friction coefficient of the pair increases first and then tends to stabilize, which indicates that the magnetic field intensifies the wear of W-20Cu/ aluminum alloy pair, and the wear mechanism is mainly adhesive wear. With the increase of magnetic field intensity, the friction surface of tungsten and copper pin tends to smooth and the surface roughness decreases by 57.9%. Application of magnetic field can reduce the degree of deformation of friction longitudinal section of tungsten and copper, and the thickness of deformation layer is reduced from 11.5 渭 m to 6.5 渭 m, which hinders the formation and expansion of cracks and slows down the generation of debris, and the magnetic field can also adsorb and refine the debris. In addition, ferromagnetic oxides appear on the friction surface of tungsten and copper pin, which indicates that the magnetic field promotes oxidation wear and thus improves the wear performance of matching pairs. The friction and wear tests of W-20Cu/45 steel under different loads, sliding velocities and magnetic field intensities show that the friction coefficient decreases with the increase of load (80 NIV 320 N), pair wear rate). The friction surface becomes rough, the average oxygen content decreases, the deformation degree of the friction longitudinal plane tends to be serious, the thickness of the deformation zone increases from 5 渭 m to 43 渭 m, and the wear mechanism changes from slight abrasive wear to severe wear. With the increase of sliding speed, the wear rate of tungsten copper pin increases and the wear rate of ring decreases, while the friction coefficient of matching pair decreases slightly, the friction surface of tungsten and copper tends to smooth, the furrow becomes shallower, and the phenomenon of partial shedding occurs. The friction coefficient and wear rate of the pair under magnetic field interference are smaller than those under the condition of no magnetic field, regardless of load or velocity. The structural changes of friction surface and longitudinal section of tungsten and copper composites and the formation of cracks in deformation zone are discussed. The friction and wear process of pin / 45 steel ring pair of tungsten and copper composite is described in detail by using model diagram. The results show that there exists deformation zone in the longitudinal section of tungsten copper friction, and the structure of dislocation in different depth of deformation zone changes. The closer it is to the friction plane of tungsten and copper, the higher the dislocation density in tungsten grain is, and even the large crack appears, and the more serious the fracture of copper grain is.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
本文编号：2338115
[Abstract]:With the expansion of the application of electromagnetic technology, more and more friction pair materials are in service under electromagnetic conditions, such as high-speed trains, electromagnetic guns and so on. The friction and wear properties of ferromagnetic materials under magnetic field environment are studied more and more at home and abroad. Rare non-ferromagnetic materials such as WCU Alu Tiu Cu and so on are studied. Among them, tungsten and copper materials are widely used in modern electronic information industry and national defense industry, so it is necessary to study their friction and wear properties and mechanism. In this paper, W-20Cu was used to match ferromagnetic material 45 steel and paramagnetic aluminum alloy respectively. The improved MPV-1500 type pin-ring friction and wear tester was used to change the magnetic field intensity. The dry friction characteristics of friction pairs are studied by loading and sliding speed. The wear mechanism of friction pairs was studied by means of scanning electron microscope (SEM), X-ray) (SEM), X-ray diffractometer (XRD), Nano-focus) and transmission electron microscope (TEM). The wear process of tungsten-copper composite is described in detail by model diagram. The main conclusions are as follows: with the increase of magnetic field intensity, the wear rate and friction coefficient of tungsten copper pin and 45 steel ring decrease with the increase of magnetic field intensity. The results show that the wear resistance and wear resistance of W-20Cu/45 steel pair are improved under magnetic field interference. With the increase of magnetic field intensity, the wear rate of tungsten and copper pin is negative when W-20Cu and aluminum alloy pair are matched. The wear rate of aluminum alloy ring increases gradually, and the friction coefficient of the pair increases first and then tends to stabilize, which indicates that the magnetic field intensifies the wear of W-20Cu/ aluminum alloy pair, and the wear mechanism is mainly adhesive wear. With the increase of magnetic field intensity, the friction surface of tungsten and copper pin tends to smooth and the surface roughness decreases by 57.9%. Application of magnetic field can reduce the degree of deformation of friction longitudinal section of tungsten and copper, and the thickness of deformation layer is reduced from 11.5 渭 m to 6.5 渭 m, which hinders the formation and expansion of cracks and slows down the generation of debris, and the magnetic field can also adsorb and refine the debris. In addition, ferromagnetic oxides appear on the friction surface of tungsten and copper pin, which indicates that the magnetic field promotes oxidation wear and thus improves the wear performance of matching pairs. The friction and wear tests of W-20Cu/45 steel under different loads, sliding velocities and magnetic field intensities show that the friction coefficient decreases with the increase of load (80 NIV 320 N), pair wear rate). The friction surface becomes rough, the average oxygen content decreases, the deformation degree of the friction longitudinal plane tends to be serious, the thickness of the deformation zone increases from 5 渭 m to 43 渭 m, and the wear mechanism changes from slight abrasive wear to severe wear. With the increase of sliding speed, the wear rate of tungsten copper pin increases and the wear rate of ring decreases, while the friction coefficient of matching pair decreases slightly, the friction surface of tungsten and copper tends to smooth, the furrow becomes shallower, and the phenomenon of partial shedding occurs. The friction coefficient and wear rate of the pair under magnetic field interference are smaller than those under the condition of no magnetic field, regardless of load or velocity. The structural changes of friction surface and longitudinal section of tungsten and copper composites and the formation of cracks in deformation zone are discussed. The friction and wear process of pin / 45 steel ring pair of tungsten and copper composite is described in detail by using model diagram. The results show that there exists deformation zone in the longitudinal section of tungsten copper friction, and the structure of dislocation in different depth of deformation zone changes. The closer it is to the friction plane of tungsten and copper, the higher the dislocation density in tungsten grain is, and even the large crack appears, and the more serious the fracture of copper grain is.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33
【参考文献】
相关期刊论文 前3条
1 计齐根,都有为;磁场热处理对Nd_2Fe_(14)B/α-Fe纳米材料磁性和微磁结构的影响[J];材料科学与工艺;2000年04期
2 高娃;张存信;;钨铜合金的最新研究进展及应用[J];新材料产业;2006年02期
3 吕大铭;钨铜材料的生产、应用与发展[J];中国钨业;2004年05期
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