【摘要】：隨著電磁技術應用范圍的擴大,越來越多的摩擦副材料在電磁工況環(huán)境下服役,如高速列車、電磁炮等,國內外對磁場環(huán)境下鐵磁性材料的摩擦磨損性能研究較多,少見非鐵磁性材料如W、Al、Ti、Cu等的研究。其中,鎢銅材料在現(xiàn)代電子信息業(yè)和國防工業(yè)領域的應用日益擴大,因此探究其摩擦磨損性能及機理十分必要。本文選用W-20Cu分別與鐵磁性材料45鋼和順磁性材料鋁合金進行配副,采用改進的MPV-1500型銷-環(huán)式摩擦磨損試驗機,通過改變磁場強度、載荷和滑動速度來研究摩擦副的干摩擦特性;利用掃描電子顯微鏡(SEM)、X-ray衍射儀(XRD)、Nano-focus三維形貌儀和透射電子顯微鏡(TEM)等儀器對材料的摩擦面、縱切面及磨屑進行微觀分析,探討摩擦副的磨損機理,并通過模型圖詳細闡述鎢銅復合材料的磨損過程。研究得到的主要結論如下:W-20Cu與45鋼配副時,隨著磁場強度的增加,鎢銅銷和45鋼環(huán)的磨損率及配副的摩擦因數(shù)均呈降低趨勢,說明磁場干涉下W-20Cu/45鋼配副的耐磨性和減磨性得到改善。W-20Cu與鋁合金配副時,隨著磁場強度的增加,鎢銅銷的磨損率相對較小為負值,而鋁合金環(huán)的磨損率逐漸增大,配副的摩擦因數(shù)先增大后趨于穩(wěn)定,說明磁場加劇了W-20Cu/鋁合金配副的磨損,其磨損機制主要為粘著磨損。W-20Cu與45鋼配副時,隨著磁場強度的增加,鎢銅銷的摩擦面趨于平滑,表面粗糙度降低了57.9%;施加磁場可降低鎢銅摩擦縱切面的變形程度,變形層厚度由11.5μm降低到6.5μm,阻礙了裂紋的生成和擴展,減緩了磨屑的生成;磁場還可吸附磨屑并使之細化;此外,鎢銅銷摩擦面上出現(xiàn)鐵磁性氧化物,說明磁場促進了氧化磨損,從而改善了配副的磨損性能。通過在不同載荷、滑動速度和磁場強度下對W-20Cu/45鋼進行摩擦磨損試驗研究表明,隨著載荷的增加(80 N~320 N),配副的磨損率均增大而摩擦因數(shù)降低;摩擦面變得粗糙,平均氧含量降低,摩擦縱切面變形程度趨于嚴重,變形區(qū)厚度由5μm增大到43μm,磨損機制由輕微的磨粒磨損轉變?yōu)閲乐啬p。隨著滑動速度的增加,鎢銅銷的磨損率增大,環(huán)的磨損率降低,而配副的摩擦因數(shù)略微降低,鎢銅摩擦面趨于平滑,犁溝變淺,且有局部脫落現(xiàn)象。無論載荷變還是速度變,與無磁場條件相比,磁場干涉下配副的摩擦因數(shù)和磨損率均相對較小。綜合探討了鎢銅復合材料摩擦面及縱切面的組織結構變化及變形區(qū)裂紋的形成,并使用模型圖詳細闡述了鎢銅復合材料銷/45鋼環(huán)配副的摩擦磨損過程。表明鎢銅摩擦縱切面存在變形區(qū),且變形區(qū)不同深度的位錯結構等缺陷發(fā)生變化,越靠近鎢銅摩擦面,鎢晶粒內位錯密度越高,甚至有大裂紋出現(xiàn),且銅晶粒破碎越嚴重。
[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.
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TB33

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本文編號：2338115