【摘要】：近年來(lái),隨著微電子、精密機(jī)械、生物醫(yī)療、航空航天等行業(yè)的迅猛發(fā)展,工業(yè)領(lǐng)域?qū)ξ⑿土慵男枨笤絹?lái)越大。微型零件的結(jié)構(gòu)尺寸微小,重量較輕,因此很難用傳統(tǒng)的機(jī)加工方法制造成形。微細(xì)電火花加工是微細(xì)加工技術(shù)的一種,該技術(shù)可加工各種超硬、脆性材料,且在加工過(guò)程中宏觀切削力很小。因此,微細(xì)電火花加工非常適合微型零件的制備。在微細(xì)電火花加工中,通過(guò)微柱狀電極對(duì)工件材料進(jìn)行逐層掃描放電加工可獲得精度較高的微結(jié)構(gòu),然而該方法存在加工效率低、電極損耗大且進(jìn)給運(yùn)動(dòng)控制復(fù)雜等缺點(diǎn)。而將三維疊層微電極應(yīng)用于微細(xì)電火花加工可有效解決上述問(wèn)題,三維疊層微電極的制備是基于分層實(shí)體制造的一種工藝,包含線切割工位和真空壓力熱擴(kuò)散焊工位,線切割用于對(duì)銅箔進(jìn)行切割從而獲得具有特定結(jié)構(gòu)的二維微結(jié)構(gòu),真空壓力熱擴(kuò)散焊將多層二維微結(jié)構(gòu)按照一定的疊層順序焊接從而擬合出三維疊層微電極。在制備含有斜面和曲面結(jié)構(gòu)的三維疊層微電極時(shí),會(huì)不可避免的出現(xiàn)臺(tái)階效應(yīng)。針對(duì)這一問(wèn)題,本文做了深入研究,主要工作和結(jié)論如下:(1)為消除純銅箔制備的三維疊層微電極在電火花放電加工獲得的微型腔中產(chǎn)生的接縫放電痕,基于Micro-DLOM工藝以鍍錫銅箔為材料制備出三維疊層微電極。詳細(xì)研究了錫膜厚度、熱擴(kuò)散焊溫度、熱擴(kuò)散焊時(shí)間對(duì)微型腔表面放電痕的影響。研究表明:在錫膜厚度為1μm(厚度為50μm)、熱擴(kuò)散焊溫度為900℃、熱擴(kuò)散焊時(shí)間為15 h,壓強(qiáng)為0.127 MPa的參數(shù)下所獲得的三維復(fù)合微電極連接可靠,具有良好的放電加工性能,將其應(yīng)用于微細(xì)電火花加工,加工結(jié)果表面的接縫放電痕基本消失。(2)臺(tái)階效應(yīng)是疊層制造中的原理性誤差。通過(guò)分析可知,分層厚度是影響臺(tái)階效應(yīng)的重要因素之一,分層厚度越大,臺(tái)階效應(yīng)越明顯。分層方向的選擇也是影響臺(tái)階效應(yīng)的重要因素之一,選擇合適的分層方向可有效提高疊層制造的精度。(3)以鍍錫銅箔為原材料制備含有斜面結(jié)構(gòu)的三維疊層微電極時(shí),在真空壓力熱擴(kuò)散焊過(guò)程中,在壓力的作用下,熔融的銅錫化合物填補(bǔ)了相鄰單元片層之間的臺(tái)階縫隙,可有效消減臺(tái)階效應(yīng)。(4)通過(guò)CAD軟件設(shè)計(jì)出含有半球結(jié)構(gòu)的三維微電極,分層后計(jì)算出各單元片層的二維結(jié)構(gòu)尺寸。使用純銅箔和鍍錫銅箔兩種材料制備了三維疊層微電極并將其應(yīng)用于微細(xì)電火花放電加工。實(shí)驗(yàn)結(jié)果表明,通過(guò)隊(duì)列電極對(duì)同一型腔進(jìn)行放電加工可獲得表面精度較高的微型腔。
[Abstract]:In recent years, with the rapid development of microelectronics, precision machinery, biomedical, aerospace and other industries, the demand for micro-parts in the industrial field is increasing. The micro-parts are small in size and light in weight, so it is difficult to form by traditional machining methods. Micro-EDM is a kind of micro-machining technology, which can process various super-hard and brittle materials, and the macro cutting force is very small in the process of machining. Therefore, micro EDM is very suitable for the fabrication of micro parts. In micro EDM, the microstructures with high precision can be obtained by layer scanning discharge machining of workpiece materials with microcylindrical electrodes. However, this method has the disadvantages of low machining efficiency, high electrode loss and complex feed motion control. The application of 3D laminated microelectrode to micro EDM can effectively solve the above problems. The fabrication of 3D laminated microelectrode is a process based on layered solid, which includes the position of wire cutting and vacuum pressure thermal diffusion welder. Wire cutting was used to cut copper foil to obtain two-dimensional microstructures with specific structure. Vacuum pressure thermal diffusion welding welded multilayer two-dimensional microstructures according to a certain stacking sequence to fit three-dimensional laminated microelectrodes. Step effect is inevitable in the fabrication of three dimensional laminated microelectrode with oblique surface and curved surface structure. To solve this problem, the main work and conclusions are as follows: (1) in order to eliminate the seam discharge marks produced by electrospark discharge machining, the three-dimensional laminated microelectrodes prepared by pure copper foil are used in the electrospark discharge machining. Three-dimensional laminated microelectrode was fabricated by using tin-plated copper foil as material based on Micro-DLOM process. The effects of tin film thickness, thermal diffusion welding temperature and thermal diffusion welding time on the discharge marks on the surface of the micro cavity were studied in detail. The results show that when the thickness of tin film is 1 渭 m (thickness is 50 渭 m), the temperature of thermal diffusion welding is 900 鈩，

本文編號(hào)：2184144