天堂国产午夜亚洲专区-少妇人妻综合久久蜜臀-国产成人户外露出视频在线-国产91传媒一区二区三区

當(dāng)前位置:主頁 > 科技論文 > 材料論文 >

磁場條件下W-20Cu復(fù)合材料的磨損行為及機(jī)理研究

發(fā)布時(shí)間:2018-11-17 14:27
【摘要】:隨著電磁技術(shù)應(yīng)用范圍的擴(kuò)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(nèi)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(lǐng)域的應(yīng)用日益擴(kuò)大,因此探究其摩擦磨損性能及機(jī)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(jìn)行配副,采用改進(jìn)的MPV-1500型銷-環(huán)式摩擦磨損試驗(yàn)機(jī),通過改變磁場強(qiáng)度、載荷和滑動(dòng)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(jìn)行微觀分析,探討摩擦副的磨損機(jī)理,并通過模型圖詳細(xì)闡述鎢銅復(fù)合材料的磨損過程。研究得到的主要結(jié)論如下:W-20Cu與45鋼配副時(shí),隨著磁場強(qiáng)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(shí),隨著磁場強(qiáng)度的增加,鎢銅銷的磨損率相對較小為負(fù)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(jī)制主要為粘著磨損。W-20Cu與45鋼配副時(shí),隨著磁場強(qiáng)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(kuò)展,減緩了磨屑的生成;磁場還可吸附磨屑并使之細(xì)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(jìn)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(dòng)速度和磁場強(qiáng)度下對W-20Cu/45鋼進(jìn)行摩擦磨損試驗(yàn)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(yán)重,變形區(qū)厚度由5μm增大到43μm,磨損機(jī)制由輕微的磨粒磨損轉(zhuǎn)變?yōu)閲?yán)重磨損。隨著滑動(dòng)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(fù)合材料摩擦面及縱切面的組織結(jié)構(gòu)變化及變形區(qū)裂紋的形成,并使用模型圖詳細(xì)闡述了鎢銅復(fù)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(cuò)結(jié)構(gòu)等缺陷發(fā)生變化,越靠近鎢銅摩擦面,鎢晶粒內(nèi)位錯(cuò)密度越高,甚至有大裂紋出現(xiàn),且銅晶粒破碎越嚴(yán)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(xué)位授予單位】:河南科技大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2015
【分類號】:TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 計(jì)齊根,都有為;磁場熱處理對Nd_2Fe_(14)B/α-Fe納米材料磁性和微磁結(jié)構(gòu)的影響[J];材料科學(xué)與工藝;2000年04期

2 高娃;張存信;;鎢銅合金的最新研究進(jìn)展及應(yīng)用[J];新材料產(chǎn)業(yè);2006年02期

3 呂大銘;鎢銅材料的生產(chǎn)、應(yīng)用與發(fā)展[J];中國鎢業(yè);2004年05期



本文編號:2338115

資料下載
論文發(fā)表

本文鏈接:http://sikaile.net/kejilunwen/cailiaohuaxuelunwen/2338115.html


Copyright(c)文論論文網(wǎng)All Rights Reserved | 網(wǎng)站地圖 |

版權(quán)申明:資料由用戶60237***提供,本站僅收錄摘要或目錄,作者需要?jiǎng)h除請E-mail郵箱bigeng88@qq.com