激光移動(dòng)刻蝕樹脂基復(fù)合材料仿真分析
發(fā)布時(shí)間：2018-10-21 18:40
【摘要】：激光技術(shù)的產(chǎn)生無疑推動(dòng)了材料加工領(lǐng)域的發(fā)展,尤其是短脈沖激光具有能量高,方向性好,無需接觸等優(yōu)點(diǎn),適合用于進(jìn)行精細(xì)加工。對(duì)于某些衛(wèi)星天線反射器表面的加工,納秒脈沖激光具有不可替代的優(yōu)勢(shì)。這類天線反射器用到一種以聚合物為基底表面涂覆金屬薄膜的復(fù)合材料,根據(jù)功能需要,需要將金屬薄膜加工成按照一定規(guī)律圖案分布的高精度功能薄膜。由于加工尺寸很小,金屬薄膜也只有幾微米的厚度,加工過程還不能損傷聚合物基底,所以傳統(tǒng)的加工方法難以達(dá)到加工要求。但是,由于影響激光刻蝕結(jié)果的因素很多,確定合適的激光刻蝕參數(shù)的過程需要耗費(fèi)時(shí)間和材料,具有一定的盲目性。因此本工作利用有限元模擬軟件COMSOL Multiphysics對(duì)激光刻蝕金屬-聚酰亞胺復(fù)合材料過程進(jìn)行模擬實(shí)驗(yàn),希望能加快實(shí)驗(yàn)進(jìn)度,降低實(shí)驗(yàn)成本。工作主要有以下幾個(gè)方面:(1)對(duì)激光刻蝕金屬材料的過程進(jìn)行分析和模型化,從激光與物質(zhì)發(fā)生的相互作用機(jī)理著手,討論了熱傳遞過程及刻蝕過程中涉及到的重要的熱物理參數(shù),介紹了有限元軟件的特點(diǎn)和計(jì)算過程。(2)建立了激光刻蝕單層和多層金屬-聚酰亞胺復(fù)合材料的幾何模型,選擇“固體傳熱”接口,對(duì)模擬過程用到的物理參數(shù)進(jìn)行了定義,將激光作為一個(gè)高能量熱源,對(duì)熱傳導(dǎo)、熱對(duì)流、熱輻射的邊界條件以及傳熱方程進(jìn)行說明,對(duì)金屬薄膜的網(wǎng)格做了加密處理。(3)考慮到脈沖激光加熱方式和連續(xù)激光的不同,模擬中將刻蝕分為加熱和冷卻階段,通過對(duì)加熱階段計(jì)算任一時(shí)刻的溫度場(chǎng),并對(duì)結(jié)果進(jìn)行分別處理。假設(shè)溫度達(dá)到氣化點(diǎn)以上即成為金屬蒸汽而被刻蝕,得到加熱結(jié)束后刻蝕輪廓和溫度場(chǎng),并作為冷卻階段的初始輸入值,如此得到一定移動(dòng)速度下連續(xù)幾個(gè)脈沖過后刻蝕深度和刻蝕輪廓。通過比較不同速度的刻蝕結(jié)果,隨激光掃描脈沖的增加,刻蝕深度增加并逐漸達(dá)到最大值,之后刻蝕深度不變,刻蝕形貌呈盆狀。移動(dòng)速度越大的激光,越早達(dá)到其最大刻蝕深度,且刻蝕深度也越小。金屬薄膜與聚酰亞胺基底界面處溫度變化相對(duì)于金屬薄膜表面在時(shí)間上有一定的滯后。(4)為了研究金屬夾層對(duì)刻蝕結(jié)果的影響,對(duì)激光刻蝕雙層金屬薄膜過程進(jìn)行了模擬,比較了涂覆純鋁和不同厚度鋁-銅金屬層,以及鋁-銅和鋁-金金屬層時(shí)激光刻蝕效果。結(jié)果顯示,每一次脈沖過后,鋁銅雙層膜與聚酰亞胺界面處峰值溫度比單層鋁薄膜低,且銅薄膜越厚,界面處溫度越低,因此選用熱導(dǎo)率大的金屬做夾層可以起到保護(hù)聚合物基底的作用。
[Abstract]:The production of laser technology has undoubtedly promoted the development of material processing, especially the short pulse laser has the advantages of high energy, good directivity, no contact and so on, so it is suitable for fine processing. Nanosecond pulse laser has irreplaceable advantages for the surface processing of some satellite antenna reflectors. This kind of antenna reflector uses a composite material coated with metal film on the polymer substrate. According to the functional requirements, the metal film needs to be processed into a high-precision functional film distributed according to a certain pattern. Because the machining size is very small and the thickness of the metal film is only a few microns, the processing process can not damage the polymer substrate, so the traditional processing method is difficult to meet the processing requirements. However, because there are many factors that affect the laser etching results, it takes time and material to determine the appropriate laser etching parameters, so it is blind to a certain extent. In this work, the finite element simulation software COMSOL Multiphysics is used to simulate the process of laser etching of metal-polyimide composites, in the hope of speeding up the experimental progress and reducing the cost of the experiment. The main works are as follows: (1) the process of laser etching of metal materials is analyzed and modeled, and the interaction mechanism between laser and matter is discussed. The important thermophysical parameters involved in the process of heat transfer and etching are discussed, and the characteristics and calculation process of the finite element software are introduced. (2) the geometric models of laser etched monolayer and multilayer metal-polyimide composites are established. The "solid heat transfer" interface is selected to define the physical parameters used in the simulation process. The laser is used as a high energy heat source to explain the boundary conditions and heat transfer equations of heat conduction, heat convection, thermal radiation. The mesh of metal film is encrypted. (3) considering the difference between pulsed laser heating and continuous laser, the etching is divided into heating and cooling stages, and the temperature field at any time is calculated by heating phase. The results were treated separately. Assuming that the temperature above the gasification point becomes metal vapor and is etched, the etching profile and temperature field are obtained after heating, and as the initial input value of the cooling stage, The etching depth and profile are obtained after several pulses at a certain moving speed. By comparing the etching results with different velocities, the etching depth increases and reaches the maximum value with the increase of laser scanning pulse, and then the etching depth remains the same, and the etching morphology is basin shape. The larger the moving speed, the earlier the maximum etching depth is reached, and the smaller the etching depth is. The temperature change at the interface between metal film and polyimide substrate has some time lag relative to the surface of metal film. (4) in order to study the effect of metal interlayer on the etching results, the laser etching process of bilayer metal film is simulated. The effect of laser etching on pure aluminum and aluminum-copper coatings with different thickness and aluminum-copper and aluminum-gold coatings was compared. The results show that the peak temperature at the interface between aluminum and copper bilayer film and polyimide is lower than that of single layer aluminum film after each pulse, and the thicker the copper film, the lower the temperature at the interface. Therefore, the use of high thermal conductivity metal as interlayer can play a role in protecting the polymer substrate.
【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB332
[Abstract]:The production of laser technology has undoubtedly promoted the development of material processing, especially the short pulse laser has the advantages of high energy, good directivity, no contact and so on, so it is suitable for fine processing. Nanosecond pulse laser has irreplaceable advantages for the surface processing of some satellite antenna reflectors. This kind of antenna reflector uses a composite material coated with metal film on the polymer substrate. According to the functional requirements, the metal film needs to be processed into a high-precision functional film distributed according to a certain pattern. Because the machining size is very small and the thickness of the metal film is only a few microns, the processing process can not damage the polymer substrate, so the traditional processing method is difficult to meet the processing requirements. However, because there are many factors that affect the laser etching results, it takes time and material to determine the appropriate laser etching parameters, so it is blind to a certain extent. In this work, the finite element simulation software COMSOL Multiphysics is used to simulate the process of laser etching of metal-polyimide composites, in the hope of speeding up the experimental progress and reducing the cost of the experiment. The main works are as follows: (1) the process of laser etching of metal materials is analyzed and modeled, and the interaction mechanism between laser and matter is discussed. The important thermophysical parameters involved in the process of heat transfer and etching are discussed, and the characteristics and calculation process of the finite element software are introduced. (2) the geometric models of laser etched monolayer and multilayer metal-polyimide composites are established. The "solid heat transfer" interface is selected to define the physical parameters used in the simulation process. The laser is used as a high energy heat source to explain the boundary conditions and heat transfer equations of heat conduction, heat convection, thermal radiation. The mesh of metal film is encrypted. (3) considering the difference between pulsed laser heating and continuous laser, the etching is divided into heating and cooling stages, and the temperature field at any time is calculated by heating phase. The results were treated separately. Assuming that the temperature above the gasification point becomes metal vapor and is etched, the etching profile and temperature field are obtained after heating, and as the initial input value of the cooling stage, The etching depth and profile are obtained after several pulses at a certain moving speed. By comparing the etching results with different velocities, the etching depth increases and reaches the maximum value with the increase of laser scanning pulse, and then the etching depth remains the same, and the etching morphology is basin shape. The larger the moving speed, the earlier the maximum etching depth is reached, and the smaller the etching depth is. The temperature change at the interface between metal film and polyimide substrate has some time lag relative to the surface of metal film. (4) in order to study the effect of metal interlayer on the etching results, the laser etching process of bilayer metal film is simulated. The effect of laser etching on pure aluminum and aluminum-copper coatings with different thickness and aluminum-copper and aluminum-gold coatings was compared. The results show that the peak temperature at the interface between aluminum and copper bilayer film and polyimide is lower than that of single layer aluminum film after each pulse, and the thicker the copper film, the lower the temperature at the interface. Therefore, the use of high thermal conductivity metal as interlayer can play a role in protecting the polymer substrate.
【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TB332
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 賈振元;趙凱;劉巍;丁立超;;工程塑料表面金屬覆層的激光定域精細(xì)去除[J];光學(xué)精密工程;2016年01期
2 劉孝麗;熊玉卿;楊建平;王瑞;吳敢;任妮;;激光刻蝕聚酰亞胺基底鋁薄膜的溫度場(chǎng)模擬[J];中國(guó)激光;2015年07期
3 朱智源;于民;胡安琪;王少南;繆e，
本文編號(hào)：2286007
本文鏈接：http://sikaile.net/kejilunwen/cailiaohuaxuelunwen/2286007.html
最近更新
教材專著
