本文關(guān)鍵詞： 激光熔覆 TC4鈦合金 納米TiC 納米Y_2O_3 溫度場仿真 顯微硬度　出處：《南京航空航天大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：本文對在TC4鈦合金表面激光熔覆制備納米顆粒增強的鈦鋁復(fù)合熔覆層進(jìn)行了基礎(chǔ)研究,主要包括納米Y_2O_3顆粒分散行為研究、激光熔覆過程仿真、TC4鈦合金表面納米顆粒增強鈦鋁復(fù)合熔覆層的制備,激光熔覆工藝參數(shù)的優(yōu)化以及熔覆層顯微組織及性能分析。本文主要開展的研究內(nèi)容如下:(1)通過對納米Y_2O_3顆粒超聲分散進(jìn)行單因素試驗,分析了分散介質(zhì)、添加粉體理論質(zhì)量分?jǐn)?shù)、分散時間對超聲分散效果的影響,對超聲工藝參數(shù)進(jìn)行了優(yōu)化。通過對納米Y_2O_3粉體球磨分散進(jìn)行正交試驗,分析了球磨轉(zhuǎn)速、球料比、球磨時間對納米Y_2O_3球磨分散效果的影響,進(jìn)行了球磨工藝參數(shù)優(yōu)化;研究了納米Y_2O_3在不同分散方式下的分散行為,得到了納米Y_2O_3最佳分散方式為“球磨/超聲”復(fù)合分散。(2)通過正交試驗,對鈦鋁原子比1:1熔覆層制備過程中的工藝參數(shù)進(jìn)行優(yōu)化;基于正交試驗結(jié)果,通過單因素試驗對不同鈦鋁原子比、不同納米TiC添加量、不同納米Y_2O_3添加量及納米TiC、納米Y_2O_3雙相增強鈦鋁復(fù)合熔覆層制備過程中的工藝參數(shù)進(jìn)行進(jìn)一步優(yōu)化,采用激光功率700W,光斑直徑1mm,掃描速度200mm·min-1,可獲得表面及熔道邊緣相對平整,熔道寬度一致性相對較好的熔覆層。(3)建立了TC4鈦合金表面壓片預(yù)置鈦鋁復(fù)合粉體激光熔覆過程三維瞬態(tài)溫度場有限元仿真模型,研究了激光功率、掃描速度和光斑直徑對熔池尺寸、熔池中心最高溫度、熔池內(nèi)溫度梯度、溫度變化率及形狀控制因子的影響規(guī)律;通過單因素仿真試驗,確立了相對合理的激光加工參數(shù)范圍;通過正交仿真試驗,比較不同激光工藝參數(shù)對溫度場的影響顯著性。討論了采用激光比能綜合表征激光功率、掃描速度和光斑直徑的局限性。(4)對不同鈦鋁原子比、不同納米TiC添加量、不同納米Y_2O_3添加量等10種成分不同的鈦鋁復(fù)合熔覆層,采用SEM、EDS、XRD及顯微硬度計進(jìn)行顯微組織、成分及顯微硬度研究分析。研究表明,各熔覆層中存在大量Ti3Al、TiAl、TiAl3金屬間化合物及少量對應(yīng)的稀土相和陶瓷相,各熔覆層顯微硬度相比于鈦合金基材都有不同程度的提升,其中納米TiC作為陶瓷相可顯著提高熔覆層硬度,納米Y_2O_3作為稀土相能有效改善顯微硬度分布的均勻性及分布深度范圍。
[Abstract]:In this paper, the laser cladding of nano-particles reinforced titanium-aluminum composite cladding layer on the surface of TC4 titanium alloy was studied, including the dispersion behavior of nano-Y _ 2O _ I _ S _ 3 particles. Simulation of Laser cladding process preparation of Nano-particles reinforced Ti-Al Composite cladding layer on TC4 Titanium Alloy Surface, Optimization of technological parameters of laser cladding and analysis of microstructure and properties of cladding layer. The main research contents in this paper are as follows: (1) the dispersion medium is analyzed by single factor experiment on ultrasonic dispersion of nanometer YSP _ 2O _ 3 particles. The effects of theoretical mass fraction of powder and dispersing time on the ultrasonic dispersion effect were optimized, and the ultrasonic process parameters were optimized. By orthogonal test on the dispersion of Y _ 2O _ 3 nano-powder, the rotational speed of ball mill and the ratio of ball to material were analyzed. The effect of ball milling time on the dispersion effect of nanometer Ys _ 2O _ 3 ball mill was optimized, and the dispersion behavior of Y _ 2O _ 3 nano-sized Ys _ 2O _ 3 in different dispersion modes was studied. The optimum dispersion mode of Y _ 2O _ 3 nanocrystalline Y _ 2O _ 3 is "ball mill / ultrasonic" composite dispersion. Through orthogonal experiment, the technological parameters in the preparation of titanium aluminum atomic ratio 1: 1 cladding layer are optimized, based on the results of orthogonal test, The technological parameters of Ti / Al / Al / Al / Ti / Al / Ti / Al / Ti / Al / Al / Ti / Al composite cladding coatings were further optimized by single factor experiments, including different ratios of Ti / Al atoms, different amount of nano-sized TiC, different amount of Y _ 2O _ 3 / S _ 2O _ 3 and nano-TiC, nano-Y _ 2O _ 3 and Y _ 2O _ 3, respectively. With laser power 700W, spot diameter 1mm, scanning speed 200mm 路min-1, the surface and fuse edge are relatively flat. The finite element simulation model of 3D transient temperature field during laser cladding process of TC4 titanium alloy surface preset Ti-Al composite powder was established, and the laser power was studied. The effects of scanning speed and spot diameter on the size of the molten pool, the maximum temperature of the molten pool center, the temperature gradient in the molten pool, the temperature change rate and the shape control factor are studied. The effects of different laser parameters on the temperature field were compared by orthogonal simulation experiments, and the effects of laser specific energy on different Ti / Al atom ratios were discussed, such as laser power, scanning speed and spot diameter. The microstructure, composition and microhardness of 10 kinds of titanium-aluminum composite cladding coatings with different content of nanometer TiC and different content of Ys / S _ 2O _ 3 were studied by means of SEM EDS-XRD and microhardness meter. There are a large number of Ti _ 3Al _ 2O _ TiAl _ (3) intermetallic compounds and a few corresponding rare earth phases and ceramic phases in each cladding layer. The microhardness of each cladding layer is improved in varying degrees compared with that of titanium alloy substrate, and the hardness of the cladding layer can be significantly improved by using nanometer TiC as ceramic phase. As rare earth phase, the distribution uniformity and depth range of microhardness distribution can be effectively improved by using Y _ 2O _ 3 nanoparticles as rare earth phase.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TG174.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 賀文雄;趙健;呂志軍;趙洪運;;鋼表面激光熔覆Ti-Al球磨粉合成復(fù)合涂層[J];焊接學(xué)報;2015年05期

2 張光耀;王成磊;高原;宋沂澤;;稀土對6063Al鎳基激光熔覆層組織及摩擦磨損性能的影響[J];摩擦學(xué)學(xué)報;2015年03期

3 劉丹;陳志勇;陳科培;唐翠;朱衛(wèi)華;何彬;王新林;;TC4鈦合金表面激光熔覆復(fù)合涂層的組織和耐磨性[J];金屬熱處理;2015年03期

4 楊銳;;鈦鋁金屬間化合物的進(jìn)展與挑戰(zhàn)[J];金屬學(xué)報;2015年02期

5 喬虹;李慶棠;符寒光;雷永平;;激光熔覆原位合成陶瓷相增強鐵基熔覆層的組織和性能[J];焊接學(xué)報;2015年01期

6 柴龍順;王存山;韓立影;張孌;;納米TiC/C對激光熔覆鎳基合金涂層組織和性能的影響[J];中國激光;2014年12期

7 王慧萍;李芳;冷培榆;嚴(yán)敏杰;;鈦合金表面激光熔覆TiC復(fù)合涂層的設(shè)計[J];應(yīng)用激光;2014年03期

8 吳東江;吳楠;楊策;馬廣義;康仁科;;預(yù)熱對Al_2O_3陶瓷激光熔覆層溫度梯度影響的模擬[J];稀有金屬材料與工程;2013年10期

9 郭純;陳建敏;姚潤鋼;周健松;張世堂;;激光熔覆原位制備Ti_3Al金屬間化合物涂層結(jié)構(gòu)及摩擦學(xué)性能[J];摩擦學(xué)學(xué)報;2013年01期

10 張可敏;鄒建新;李軍;于治水;王慧萍;;TC4鈦合金表面激光熔覆法制備Y_2O_3顆粒增強Ni/TiC復(fù)合涂層(英文)[J];Transactions of Nonferrous Metals Society of China;2012年08期

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