本文選題：激光近凈成形　切入點(diǎn)：數(shù)值分析　出處：《合肥工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：激光近凈成形技術(shù)是一種以激光為能量源,采用預(yù)鋪粉或同軸送粉的送料方式,在基體上熔覆材料粉末從而生成立體工件的新型制造技術(shù)。該技術(shù)能對(duì)傳統(tǒng)工業(yè)難以制造的復(fù)雜金屬零件進(jìn)行直接成形,其快熱快冷的加工特性可以改進(jìn)工件的物理性質(zhì),因而普遍運(yùn)用于航空航天、汽車制造、模型開發(fā)等領(lǐng)域。但該技術(shù)發(fā)展尚不充分、很多基礎(chǔ)性研究尚待完善,工件成形時(shí)常常出現(xiàn)邊緣凸起、斷裂以及脫離基板等問題,嚴(yán)重影響了成形精度和成形質(zhì)量。因此本文從激光近凈成形技術(shù)的基礎(chǔ)研究出發(fā),采用數(shù)值模擬方法對(duì)薄壁工件的溫度場、速度場及應(yīng)力場進(jìn)行分析。本文基于控制容積法,結(jié)合數(shù)值傳熱學(xué)、流體力學(xué)的相關(guān)理論,在Matlab軟件中建立了激光近凈成形過程的溫度-速度場耦合模型。利用模型計(jì)算工件在任意時(shí)刻的溫度分布和熔池形貌,重點(diǎn)分析了多層工件的熔池形貌衍變過程。隨后通過計(jì)算成形過程中的有效送粉量,預(yù)測了薄壁工件的成形高度,并解釋了工件邊緣凸起產(chǎn)生的原因。最后建立CCD成像系統(tǒng)拍攝熔池形貌,并利用成像實(shí)驗(yàn)驗(yàn)證了數(shù)值模型的正確性。本文基于有限元法,在ANSYS熱力學(xué)分析軟件中,采用間接耦合的方法建立了薄壁工件的溫度-應(yīng)力場耦合模型。利用生死單元技術(shù)模擬了熱源的移動(dòng)和材料的添加過程。文中重點(diǎn)探究了工件的等效應(yīng)力分布、各應(yīng)力分量的分布以及關(guān)鍵路徑上的應(yīng)力分布,從而解釋了工件斷裂以及脫離基板的原因。
[Abstract]:Laser near net forming technology is a kind of laser energy source, the feeding method of pre powder or coaxial powder, a new manufacturing technology on the base of cladding material powder to generate three-dimensional workpieces. The technology of traditional industries is difficult to manufacture complex metal parts for direct forming, can improve the physical properties of the workpiece the processing characteristics of the rapid heating and rapid cooling of the thus widely used in aerospace, automobile manufacturing, model development and other fields. But the technology development is not sufficient, a lot of basic research needs to be improved, workpiece forming often convex edge, and the substrate from the fracture problem, seriously affecting the forming precision and forming quality. Therefore this article embarks from the basic research of near net forming technology of laser, using the method of numerical simulation of temperature field of thin-walled workpiece, analyzes the velocity field and stress. In this paper, the control volume method based on node Number value of heat transfer, the theory of fluid mechanics, in the Matlab software, the coupling model of near net forming process of laser temperature velocity field is established. The temperature distribution and the weld shape calculation of workpiece at any time by using the model, analyzes the weld shape evolution of multilayer workpiece. By calculating the effective amount of powder forming subsequently send process, predict the forming height of thin-walled workpiece, and explains the workpiece edge from the bulge. A CCD imaging system shooting pool morphology and verify the correctness of the numerical model by using the imaging experiment. Based on the finite element method in ANSYS software, the thermodynamic analysis of thin-walled workpiece temperature should be the coupling model of stress field is established using indirect coupling method. The process was simulated by adding a moving heat source and material life and death element technology. This paper focuses on the equivalent stress of the workpiece The distribution of the distribution of the stress components and the stress distribution on the critical path, which explains the reasons for the fracture of the workpiece and the separation of the substrate.

【學(xué)位授予單位】：合肥工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN249;O414.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊膠溪;靳延鵬;張寧;;激光熔覆技術(shù)的應(yīng)用現(xiàn)狀與未來發(fā)展[J];金屬加工(熱加工);2016年04期

2 張冬云;吳瑞;張暉峰;劉臻;;激光金屬熔覆成形過程中溫度場演化的三維數(shù)值模擬[J];中國激光;2015年05期

3 王新堂;張金一;DU Yingang;;00Cr17Ni14Mo2不銹鋼高溫力學(xué)性能[J];建筑材料學(xué)報(bào);2015年05期

4 王華明;張凌云;李安;湯海波;張述泉;方艷麗;李鵬;;高性能航空金屬結(jié)構(gòu)材料及特種涂層激光熔化沉積制備與成形研究進(jìn)展[J];金屬熱處理;2008年01期

5 楊健;黃衛(wèi)東;陳靜;楊海歐;;TC4鈦合金激光快速成形力學(xué)性能[J];航空制造技術(shù);2007年05期

6 曾錫琴;朱小蓉;;激光選區(qū)燒結(jié)成型材料的研究和應(yīng)用現(xiàn)狀[J];江蘇技術(shù)師范學(xué)院學(xué)報(bào);2005年06期

7 張凱,劉偉軍,尚曉峰,王天然;激光直接快速成形金屬材料及零件的研究進(jìn)展(下)——國內(nèi)篇[J];激光雜志;2005年05期

8 鄧琦林,胡德金;激光熔覆快速成型致密金屬零件的試驗(yàn)研究[J];金屬熱處理;2003年02期

9 董俊慧,霍立興,張玉鳳;環(huán)焊縫管道焊接應(yīng)力應(yīng)變?nèi)S有限元分析[J];機(jī)械工程學(xué)報(bào);2001年12期

10 楊森,鐘敏霖,張慶茂,劉文今;激光快速成型金屬零件的新方法[J];激光技術(shù);2001年04期

相關(guān)博士學(xué)位論文 前2條

1 宋以國;多焊縫管板結(jié)構(gòu)焊接工藝與殘余應(yīng)力分析[D];哈爾濱工程大學(xué);2013年

2 李鵬;基于激光熔覆的三維金屬零件激光直接制造技術(shù)研究[D];華中科技大學(xué);2005年

相關(guān)碩士學(xué)位論文 前3條

1 趙海玲;激光熔覆熔池溫度場和流場的數(shù)值模擬[D];燕山大學(xué);2013年

2 孟亞惠;304、410S和E01不銹鋼高溫力學(xué)性能研究[D];蘭州理工大學(xué);2009年

3 劉曉苗;特殊形狀貫穿件焊接殘余應(yīng)力和疲勞分析[D];哈爾濱工程大學(xué);2009年

，

本文編號(hào)：1630497