【摘要】：具有一定尺寸和分布的微坑陣列在改善摩擦副摩擦性能方面發(fā)揮著重要的作用,它不僅能夠減小摩擦副之間的摩擦系數(shù),還能夠降低磨損提高摩擦副的使用壽命。例如,航天齒輪泵作為水循環(huán)系統(tǒng)的傳動部件,其齒輪端面和殼體密封端面磨損嚴重時會嚴重影響齒輪泵的工作效率和整個水循環(huán)系統(tǒng)的可靠運行。研究表明在齒輪泵殼體密封端面設計具有一定尺寸和分布的微坑陣列可以有效地改善潤滑狀況,降低齒輪與密封端面的磨損量,從而提高齒輪泵的運行效率和使用壽命。微坑陣列已在摩擦學、熱能交換以及生物醫(yī)學等領域得到重要的應用,因此,如何高效、高精度加工微坑陣列成為一個研究的重點。目前,微坑陣列的加工方法主要有機械加工、激光加工、電火花加工、磨粒流加工和電解加工。其中,電解加工技術因在加工中無熱影響區(qū)、無熱應力、電極無損耗、易于實現(xiàn)微細加工等優(yōu)點,成為研究的熱點。易實現(xiàn)大面積微坑陣列一次加工成形的光刻微細電解加工技術是目前備受關注的一種微坑陣列電解加工方法。光刻微細電解加工技術是利用光刻工藝在工件表面制作具有鏤空圖案的模板,從而對工件進行選區(qū)域電解加工的方法。其每個工件都需要經(jīng)過涂膠、前烘、曝光、顯影和后烘等一系列工藝,電解加工之后還需要除去光刻膠,制作過程復雜,生產(chǎn)流程長。在一次加工大量微坑時存在微坑尺寸不一致,加工精度差的問題。此外,單個微坑的形貌也不規(guī)則,在微坑中心位置容易形成凸起的結構(通常稱之為“孤島”)。針對上述問題,本文探索了提高微坑光刻電解加工的加工精度以及消除“孤島”的方法,并將厚層活動模板引入微坑陣列的電解加工,開展微坑陣列的厚層模板電解加工技術研究。本文完成的研究內(nèi)容主要包含以下幾個部分:(1)提出采用正電位輔助陽極和厚層模板方法,提高了微坑陣列電解加工的加工精度,消除了微坑電解加工的“孤島”現(xiàn)象。仿真和試驗結果表明,具有合適正電位的輔助陽極可以有效改善微坑陣列的加工精度,此外使用厚層模板不僅能夠改善微坑陣列的加工精度,而且有效避免了微坑“孤島”現(xiàn)象的產(chǎn)生。(2)發(fā)明一種聚二甲基硅氧烷(PDMS)微孔模板的制作方法。通過改進光刻工藝,并結合真空輔助模塑法,探索出一種新的PDMS微孔模板的制作方法,并利用該方法成功制備出孔徑為50μm和100μm,厚度250μm的PDMS厚層微通孔模板。由于PDMS具有良好的化學穩(wěn)定性,在電解加工中可以重復使用,這可以縮短工藝準備時間,從而提高微坑陣列的生產(chǎn)效率。(3)優(yōu)選出適合PDMS厚層模板微細電解加工的電解液流動模式。通過對不同的電解液流動模式下電解加工微坑質(zhì)量對比分析,優(yōu)選出一種電解液正向流動模式,并設計出具有群縫結構的陰極。結果表明,采用此種流動模式不僅保證了PDMS厚層模板與工件的貼合,還避免了加工中由于柔性模板變形導致的微坑形貌變形,有助于實現(xiàn)高質(zhì)量微坑陣列的微細電解加工。(4)發(fā)現(xiàn)PDMS厚層模板電解加工具有對加工參數(shù)不敏感的優(yōu)點,闡明了該技術能夠獲得高加工精度的原因。試驗結果表明,微坑的深度僅隨加工時間改變,而對加工電壓敏感性低。此外,隨加工電壓和時間的變化,微坑的直徑均僅有3~5μm的側(cè)向腐蝕,具有高的加工精度。通過電流效率計算、流場仿真以及CCD在線觀測,指出采用PDMS厚層模板電解加工時,加工區(qū)的電解液始終處于高壓低流速狀態(tài),此狀態(tài)不僅能夠減小氣泡的體積也減緩了氣泡和不溶性產(chǎn)物的排出,而且大部分氣泡和產(chǎn)物的混合體會聚集在微坑的邊緣,有效降低了微坑電解加工的側(cè)向腐蝕,提高了微坑電解加工的加工精度。(5)開展了微坑陣列的PDMS厚層模板微細電解加工應用研究。對不銹鋼密封端面進行微坑陣列的電解加工,使齒輪泵使用壽命提高了一倍;在鍍鉻層表面微細電解加工出微坑陣列,摩擦學試驗結果表明,方形微坑陣列比圓形微坑陣列有更加明顯的減摩效果,具有方形微坑陣列的表面較光滑表面的最高減摩率可達40%。
[Abstract]:The micro-pit array with a certain size and distribution plays an important role in improving the friction performance of the friction pair, and not only can reduce the friction coefficient between the friction pairs, but also can reduce the wear and improve the service life of the friction pair. For example, as a transmission component of a water circulation system, a space gear pump can seriously affect the working efficiency of the gear pump and the reliable operation of the whole water circulation system when the gear end surface and the seal end face of the shell seal are seriously worn. The research shows that the design of a micro-pit array with a certain size and distribution on the sealing end surface of the gear pump shell can effectively improve the lubrication condition, reduce the wear amount of the gear and the sealing end face, and improve the operation efficiency and the service life of the gear pump. The micro-pit array has been widely used in the fields of tribology, thermal energy exchange and biomedicine. Therefore, how to process the micro-pit array with high efficiency and high precision becomes the focus of a research. At present, the processing method of the micro-pit array mainly includes machining, laser processing, electric spark machining, abrasive flow processing and electrolytic processing. in which, the electrolytic processing technology has the advantages of no thermal influence area, no thermal stress, no electrode loss, easy realization of fine processing and the like in the processing, and has become the hot spot of the research. The invention relates to a micro-pit array electrolytic processing method which is easy to realize one-time machining and forming of a large-area micro-pit array. the invention relates to a photoetching micro-electrolysis processing technology, which comprises the following steps of: making a template with a blank pattern on the surface of a workpiece by using a photoetching process, so as to carry out selective area electrolysis processing on the workpiece. each of the workpieces needs to be subjected to a series of processes such as gluing, pre-drying, exposure, developing and post-drying, and the photoresist is also required to be removed after the electrolytic processing, and the manufacturing process is complicated and the production flow is long. and the problem that the size of the micro-pits is not uniform and the machining accuracy is poor is solved when a large number of micro-pits are processed at a time. In addition, the topography of a single pit is also irregular, and a raised structure (generally referred to as a 鈥淕udao鈥，

本文編號：2388253