本文選題：微流道 + 熱效應(yīng)�。� 參考：《廣東工業(yè)大學(xué)》2017年碩士論文

【摘要】：微流控芯片技術(shù)是一種在微米甚至納米尺度的低微通道結(jié)構(gòu)中控制體積為皮升甚至納升的流體進(jìn)行流動并傳質(zhì)、傳熱的技術(shù),是工程、物理、化學(xué)、生物、納米技術(shù)等眾多學(xué)科交叉的技術(shù)領(lǐng)域。目前,微流控芯片的制備主要使用光刻工藝來保證微米級的尺寸精度,而光刻工藝環(huán)節(jié)眾多,操作和制備手段極其復(fù)雜且繁瑣。本課題組提出了微流控芯片的快速批量化制造,而模具是工業(yè)中批量化制造的最佳方案,因此在金屬材料上加工出形貌規(guī)則的微結(jié)構(gòu)至關(guān)重要。材料微結(jié)構(gòu)的制備主要使用了微細(xì)加工技術(shù),包括精密機(jī)械加工、電火花加工、微細(xì)電解加工、LIGA技術(shù)和激光加工等多種加工方法。由于微流芯片多在一百微米尺度下,相比于上述其他加工方法,激光加工具有光斑尺寸小、無需制備電極和刀具、無需配置溶液等特點(diǎn),所以對激光加工微流道進(jìn)行實(shí)驗(yàn)和研究很有必要。本文以激光微加工技術(shù)和激光拋光技術(shù)為基礎(chǔ),以制備形貌規(guī)則、底部平滑的微流道為目標(biāo),提出了激光加工微流道和流道底部表面質(zhì)量改善的復(fù)合工藝方案。主要研究方法和結(jié)論如下:(1)從激光微加工的機(jī)理出發(fā),概述了激光與材料相互作用的機(jī)理,分析了本實(shí)驗(yàn)設(shè)備的合理性。介紹了激光加工的表面效應(yīng),并通過數(shù)值分析,計(jì)算Fe對波長為1064nm的紅外激光的吸收率,求得吸收率理論值約為0.36。結(jié)合激光作為電磁波對電子和離子的影響,在激光材料產(chǎn)生的熱效應(yīng)方面分析了納秒激光和飛秒激光的區(qū)別,得出納秒激光必然存在明顯熱傳導(dǎo)效應(yīng)的結(jié)論。由材料的熱物理性質(zhì)出發(fā),考慮金屬材料發(fā)生相變時(shí)的熔化潛熱和氣化潛熱,在不考慮脈寬影響的前提下,粗略估算了加工過程中使用的最小單脈沖能量。(2)對316L不銹鋼進(jìn)行激光微加工單因素實(shí)驗(yàn),然后繪制流道寬度/深度趨勢圖,展示代表性的流道形貌,用以研究激光微加工中尺寸和形貌的規(guī)律。結(jié)果表明:掃描速度過低,流道出現(xiàn)過熔和加工表面兩側(cè)的燒蝕現(xiàn)象,速度過低,流道直線度下降;脈沖寬度越小,加工得到的形貌越規(guī)律;掃描次數(shù)越多,流道形貌越差,流道底部的波動越明顯。(3)借助激光拋光技術(shù),對單脈沖能量和掃描速度進(jìn)行流道底部表面質(zhì)量改善的單因素實(shí)驗(yàn),然后測量流道底部表面粗糙度Rt的值,并繪制相應(yīng)的曲線。結(jié)果表明:隨著單脈沖能量的增大,流道底部表面粗糙度Rt值先下降后上升;隨著掃描速度的逐漸增大,流道底部的表面粗糙度Rt值同樣先下降后上升。(5)在COMSOL軟件環(huán)境中使用固體熱傳導(dǎo)模塊,將激光模擬為高斯熱源,對單脈沖激光加工過程中材料表面的溫度場分布、氣化寬度和激光作用后的冷卻過程進(jìn)行仿真模擬。結(jié)果表明:相鄰兩個(gè)激光脈沖的時(shí)間間隔內(nèi),材料表面光斑中心溫度在激光脈沖寬度內(nèi)迅速以指數(shù)形式升高和下降,在5μs范圍內(nèi)迅速降低至材料的熔化溫度以下,在下一個(gè)脈沖到來之前材料已經(jīng)冷卻,這表明脈沖激光加工具有瞬時(shí)性;單脈沖能量越高,材料表面最高溫度越大,氣化寬度越大;脈沖寬度越短,材料表面溫度越高,氣化寬度越大;與脈沖寬度變化相比,單脈沖能量的變化對氣化寬度的影響更明顯。
[Abstract]:Microfluidic chip technology is a fluid for skin or even nanoliter volume control a small channel structure in micro or nano scale in the flow and mass transfer, heat transfer technology, engineering, physics, chemistry, biology, nanotechnology and many other interdisciplinary technical field. At present, the main preparation of microfluidic chip the use of lithography process to ensure the accuracy of the size of micron, and the lithography process part number, operation and preparation methods are extremely complex and tedious. This paper puts forward the rapid mass production of microfluidic chip, and the mold is in the industrial batch manufacturing best scheme, so the processing micro structure plays an important role in metal morphology the micro structure of the material. The material preparation is mainly used microfabrication technology, including precision machining, EDM, micro machining, LIGA technology and laser processing and other processing methods. The microfluidic chip in one hundred micron scale, compared with the other processing methods, laser processing with a small spot size, without preparation of electrode and tool, without configuration solution, so it is necessary for laser processing of micro channel experiments and research. In this paper, laser micro processing technology and laser polishing technology based on the rules of morphology for the preparation, micro channel bottom smooth as the goal, put forward the composite process scheme of laser processing and surface quality of micro channel flow at the bottom of improvement. The main research methods and conclusions are as follows: (1) starting from the mechanism of laser micro machining, the mechanism of interaction between laser and material, analysis the rationality of experimental equipment. The effect of laser surface processing, and through the numerical analysis, the calculation of Fe wavelength of 1064nm infrared laser absorption rate, absorption rate obtained theoretical value is about 0.36. with shock As the optical effects of electromagnetic waves on electrons and ions, thermal effect in laser materials analysis of the difference between nanosecond laser and femtosecond laser, teller second laser must exist obvious heat conduction effects. Starting from the thermal physical properties of material, considering the metal material occurs when the phase transformation latent heat and latent heat of vaporization. Without considering the influence of pulse width, a rough estimate of the process used in the minimum pulse energy. (2) of 316L stainless steel by laser micro machining experiment of single factor, and then draw the channel width / depth trend chart show channel morphology representative, to study the size and morphology of laser micro processing in the law. The results show that the scanning speed is too low, the channel had ablation phenomenon, welding and machining surface on both sides of the low speed flow linearity decreased; pulse width is smaller, the more regular morphology processing; scanning The more the number of channel morphology is worse, at the bottom of the channel fluctuations are more obvious. (3) by means of laser polishing technology, experiments on the single factor to improve the surface quality of the channel at the bottom of the single pulse energy and scanning speed, and then measuring the channel bottom surface roughness value of Rt, and draw the corresponding curve. The results show that: with the increase of single pulse energy flow, the bottom surface roughness Rt value decreased first and then increased; with the increasing of scanning speed, the bottom of the channel surface roughness Rt value also decreased and then increased. (5) the use of solid heat conduction module in the COMSOL software environment, the simulation of laser Gauss heat source on the surface material of single pulse in the laser cutting process of temperature field simulation of cooling process of gasification width and after laser irradiation. The results showed that two adjacent laser pulses within a time interval, the surface temperature in the laser spot center materials The optical pulse width in the rapid rise and fall in exponential form, below the melting temperature decreased rapidly to the material in the 5 s range, in the next pulse before the arrival of material has been cooling, which indicates that the pulse laser processing is temporary; the single pulse energy is high, the high temperature of the material surface, the width of gasification big; the shorter the pulse width, the material surface temperature is higher, compared with the width of the gasification; the pulse width changes, changes of single pulse energy on the gasification width is more obvious.

【學(xué)位授予單位】：廣東工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TH16

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 戴玉堂;徐剛;崔健磊;;光纖三維微結(jié)構(gòu)的157nm激光微刻蝕[J];光電子.激光;2010年02期

2 陳林,楊永強(qiáng);激光拋光機(jī)理及應(yīng)用[J];表面技術(shù);2003年05期

3 李祥友,曾曉雁;激光精密切割不銹鋼模板割縫質(zhì)量控制[J];中國激光;2002年02期

4 賀安之,卞保民;微粒光散射理論與測試技術(shù)研究[J];激光雜志;2000年03期

，

本文編號：1761029