English  |  正體中文  |  简体中文  |  Items with full text/Total items : 26294/26889 (98%)
Visitors : 10781790      Online Users : 297
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ksu.edu.tw/handle/987654321/6339

    Title: 摩擦磁化機制之量化研究與應用
    Quantitative study and application on the tribo-magnetization mechanisms
    Authors: 張育斌
    Keywords: 滑動速率
    TiN coating
    Sliding speed
    Normal load
    Surface magnetization
    TiN coating
    Date: 2007-07-31
    Issue Date: 2009-12-30 10:29:05 (UTC+8)
    Abstract: 本文研究鐵自配於乾燥且嚴重磨耗條件下摩擦對表面磁化之影響。藉由比較滑動速率與垂直負荷對表面磁化的影響,本文因此可釐清摩擦磁化之物理矛盾問題。結果顯示:劇烈的摩擦現象為形成表面磁化的原因,並且,鐵自配摩擦時之動態最大飽和值僅約為18G。當摩擦試驗後表面磁化即迅速衰減至0~1G 之範圍。隨著滑動速率之增加,表面磁化會明顯呈現逐漸減小的趨勢。這是因為高摩擦速度而使得真接觸區域產生明顯溫昇及氧化物,而遮蔽了磁區,且磁區也會因熱震動而導致方向趨於凌亂,故能產生消磁現象。平均表面磁化與滑動速率呈現反比之關係。在較輕負荷下,表面磁化極不明顯。當垂直負荷超過30N 時,平均表面磁化會明顯隨垂直負荷之增加而線性正比例的增加,平均表面磁化並與wear loss 之變化趨勢相當吻合,這是因為產生嚴重磨耗及材料轉移時,此時因為氧化膜破裂而新鮮鐵裸露,且鐵材料之磁區受到摩擦活化及地球磁場之影響而扭向同一方向,故能產生表面磁化現象。本研究最後並提出能量及質量之不同觀點以釐清摩擦對表面磁化的影響。並且,一般而言,以往動態評估薄膜抗磨耗性能的參數皆為摩擦係數,然而,從過去的研究文獻中發現,摩擦係數的靈敏性常常並不夠高,因此,本論文提出使用表面磁化的變化作為評估薄膜抗磨耗性能的新方法。使用工具鋼(SKD11)為基材,分別鍍上物理氣相沉積(CVD)及化學氣相沉積(PVD)之TiN coatings 進行乾摩擦實驗,研究垂直負荷對不同TiN coatings 之摩擦及磨耗性能。從實驗中發現表面磁化之動態變化較傳統摩擦係數之情況易判斷出薄膜破裂之瞬間及耐久壽命,因此,綜合實驗結果可發現表面磁場之動態變化具有發展成為評價不同表面處理方式之磨潤性能的發展潛力。
    The effects of friction on tribo-magnetization mechanisms for self-mated iron pairs under dry friction were experimentally investigated in this study. By comparing the effects of sliding speeds and normal loads on surface magnetization, the physical contradiction in frictional magnetization can therefore be classified. Results showed that severe friction phenomena are the pre-requisite conditions for tribo-magnetization to occur. The maximum dynamic saturated value of tribo-magnetization for the self-mated iron pairs during the friction process was found to be only about 18G but rapidly decreased to the range of 0~1G after the test. It was also found that tribo-magnetization decreased significantly with increasing sliding speed. This was due to a rise in surface temperature and the presence of oxide materials at the actual contact areas from higher sliding speeds. The magnetic domains were also randomly oriented due to thermal vibration, which explained surface demagnetization with increasing sliding speed. In general, the average tribo-magnetization was inversely proportional to the sliding speed. Under small normal loads, tribo-magnetization was insignificant. For normal loads exceeding 30N, the average tribo-magnetization increased linearly with increasing normal load. It was revealed that variations of the average tribo-magnetization coincided with wear losses under heavy normal loads. The reasons were that as the oxide film broke, fresh ferromagnetism was exposed to severe wear and material transfer. The orientation of the magnetic domains was caused by both frictional activation and the earth’s magnetic field. Tribo-magnetization was thus significantly increased by friction and wear with increasing normal load. Finally, this study proposed two perspectives on energy and material to clarify the physical contradictions of the tribo-magnetization. Moreover, generally speaking, the major parameter which has been used to monitor the dynamic tribological properties of the films over the past decades is friction coefficient. However, it has shown low in sensitivity for many cases. Therefore, it is necessary to introduce more improved physical measurements other than the friction coefficient to monitor and control the film tribological characteristics in sliding contacts. In view of this, the novel technology of using instead surface magnetization variations for evaluating the wear-resistant properties of the films is proposed. The experiment was conducted by the pairs of SUS304 rubbing with SKD11 substrate with different TiN films (PVD and CVD) on the surface at different normal loads in dry friction process.The effects of normal loads on the friction and wear properties for the die surfaces with different TiN films were investigated. The experimental results show that the ontinuous surface magnetization variations can be used to determine the timing of film fracture and the endurance life more accurately than that by the friction coefficient variations as usual. Therefore, the novel method of using surface magnetization variations does show great potentialities for evaluating the tribological properties of the die surfaces with different TiN films.
    Appears in Collections:[機械工程系所] 研究計畫

    Files in This Item:

    File Description SizeFormat
    952221E168009.pdf1147KbAdobe PDF291View/Open

    All items in KSUIR are protected by copyright, with all rights reserved.

    ©Kun Shan University Library and Information Center
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback