本文選題：YAG + 微波輔助均相沉淀法��； 參考：《山東大學(xué)》2011年博士論文

【摘要】：YAG透明陶瓷因其具有熱導(dǎo)率高、熱膨脹系數(shù)小、硬度大、光學(xué)特性優(yōu)異等眾多特點(diǎn),而成為開發(fā)光學(xué)器件首選的基質(zhì)材料。 本文以廉價的無機(jī)鹽為原料,分別采用碳酸氫銨共沉淀法和微波輔助均相沉淀法制備YAG納米粉體,通過真空燒結(jié),成功地制備了YAG透明陶瓷。首次利用微波輔助均相沉淀法制備的Nd:YAG透明陶瓷實(shí)現(xiàn)了激光輸出,證明此方法在制備Nd:YAG透明陶瓷方面有一定的潛力。 論文首次重點(diǎn)研究了在微波輔助均相沉淀法制備Nd:YAG納米粉體過程中陳化作用(陳化過程中狀態(tài)、時間、溫度和濕度)對Nd:YAG納米粉體的影響,進(jìn)而找出了制備分散性均良好和可燒結(jié)性優(yōu)良的Nd:YAG納米粉體的最佳工藝,并對真空燒結(jié)YAG陶瓷透明機(jī)理進(jìn)行了初步地探討。論文主要研究內(nèi)容及結(jié)論包括： 1)在碳酸氫銨沉淀法制備YAG納米粉體過程中重點(diǎn)研究了母鹽溶液的濃度、母鹽溶液的滴加速度及有機(jī)溶劑對制備YAG納米粉體的影響： (1)母鹽溶液的濃度對生成YAG前驅(qū)體及煅燒粉體的形貌產(chǎn)生了顯著的影響。只有低濃度的母鹽溶液([Y3+]=0.08M,[Al3+]=0.13M)生成的前驅(qū)體具有較好的分散性,更有利于獲得顆粒分散均勻,形狀近似球形的YAG納米粉體。母鹽溶液的濃度對合成的YAG納米粉體的物相的影響并不是太明顯,但相對來講低溶度的母鹽溶液能夠獲得具有更好的YAG物相的納米粉體； (2)母鹽溶液的滴加速度的影響比較顯著。當(dāng)母鹽溶液和NH4HC03沉淀劑溶液混合速度比較快時更容易獲得具有較好的YAG物相的納米粉體,且低濃度的母鹽溶液和NH4HC03溶液混合速度比較快時,更容易獲得具有較好物相的YAG納米粉體,同時生成YAG納米粉體具有良好的燒結(jié)性； (3)少量有機(jī)溶劑(有機(jī)溶劑與母鹽溶液體積比為1：5)對YAG納米粉體的物相和形貌有一定影響。加入少量乙醇作為溶劑對獲得純相YAG納米粉體具有較好效果,低濃度母鹽溶液中加入少量乙醇和NH4HC03沉淀劑溶液快速混合可以獲得純物相和顆粒形貌很好的YAG納米粉體,因此母鹽溶液中加入少量的乙醇對制備性能穩(wěn)定的YAG納米粉體有一定作用。實(shí)驗(yàn)中所制備的YAG粉體能夠燒結(jié)出透明陶瓷,證明通過系統(tǒng)地控制上述三個因素可以得到具有良好燒結(jié)性的YAG納米粉體。 2)在微波輔助均相沉淀法制備Nd:YAG納米粉體過程中研究了母鹽溶液的濃度、尿素用量、分散劑(NH4)2S04的用量和陳化作用對制備Nd:YAG納米粉體的影響： (1)反應(yīng)物母鹽溶液的濃度、尿素用量和分散劑(NH4)2S04的用量對制備Nd:YAG納米粉體性質(zhì)的影響是基本應(yīng)該考慮的,在本實(shí)驗(yàn)中反應(yīng)母鹽溶液的濃度為[Nd3++Y3+]=0.06M,[A13+]=0.1M,尿素與金屬離子的物質(zhì)的量比25：1,分散劑(NH4)2S04的用量為母鹽溶液中所有硝酸鹽質(zhì)量的8%,這些值為制備Nd:YAG納米粉體最佳值； (2)陳化狀態(tài)和陳化時間對Nd:YAG納米粉體的物相和形貌的影響很明顯。Nd:YAG前驅(qū)體在反應(yīng)釜中陳化的效果比在空氣中的陳化效果更好,更有利于獲得顆粒尺寸均勻,形狀近似橢圓的Nd:YAG納米粉體,但陳化過程中仍舊需要一定的物質(zhì)交換,表現(xiàn)出陳化作用對外界環(huán)境的敏感性。Nd:YAG前驅(qū)體在反應(yīng)釜中隨著陳化時間的變化,獲得的Nd:YAG納米粉體的顆粒尺寸先減小后增大,在本實(shí)驗(yàn)中是在反應(yīng)釜中陳化6天后得到的Nd:YAG納米粉體的粒徑最小； (3)陳化環(huán)境的濕度和溫度對Nd:YAG納米粉體物相和形貌的影響比較明顯。濕度和溫度對Nd:YAG納米粉體的影響有一定的依存關(guān)系,因此在制備Nd:YAG納米粉體過程中必須控制陳化環(huán)境合適的濕度和溫度,目前本實(shí)驗(yàn)的濕度控制在30%-50%,溫度在25℃,能夠得到的性質(zhì)較好的Nd:YAG納米粉體。 3)為了成功地制備Nd:YAG透明激光陶瓷,Nd:YAG納米粉體必須要具有的性質(zhì)： (1)為了獲得Nd:YAG透明陶瓷,必須首先制備出具有純YAG相的Nd:YAG納米粉體； (2)為了獲得高質(zhì)量的Nd:YAG納米粉體,必須嚴(yán)格控制影響Nd:YAG納米粉體性質(zhì)的各種因素。所制備的Nd:YAG納米粉體必須在物理和化學(xué)性質(zhì)上具有相對穩(wěn)定性,同時也應(yīng)該具有一定的燒結(jié)活性來保證Nd:YAG透明陶瓷的成功燒結(jié),因此制備的Nd:YAG納米粉體要具有較小尺寸的顆粒、較窄的顆粒尺寸分布和較低的缺陷密度,這樣的Nd:YAG納米粉體將有助于獲得具有良好性能的Nd:YAG透明陶瓷； (3)最終所制備的Nd:YAG納米粉體除了具有純YAG相,較小尺寸的顆粒、較窄的顆粒尺寸分布和較低的缺陷密度外,還應(yīng)具有均勻的微觀組分和適當(dāng)?shù)幕瘜W(xué)計量比的偏移程度,這些性質(zhì)最終保證能夠獲得具有良好性能的Nd:YAG透明陶瓷； (4)在溫度在25℃,濕度在30-50%之間,反應(yīng)釜中陳化6天的Nd:YAG納米粉體真空1730℃燒結(jié)10h獲得的經(jīng)過精拋的Nd:YAG透明陶瓷片激光的激光輸出能量可達(dá)305 mW,斜率為5.1%。
[Abstract]:YAG transparent ceramics have many characteristics, such as high thermal conductivity, small thermal expansion coefficient, large hardness and excellent optical properties, and become the first choice material for developing optical devices.
In this paper, YAG nano powders were prepared by the method of ammonium bicarbonate co precipitation and microwave assisted homogeneous precipitation, and the transparent YAG ceramics were prepared by vacuum sintering, and the Nd:YAG transparent ceramics prepared by microwave assisted homogeneous precipitation method were realized for the first time. It was proved that this method was used in the preparation of Nd:YAG penetration. The bright pottery has a certain potential.
In this paper, the effect of aging (state, time, temperature and humidity) on the Nd:YAG nano powders during the preparation of Nd:YAG nano powder by microwave assisted homogeneous precipitation method was emphatically studied. The best process of preparing Nd: YAG nano powder with good dispersibility and good sintering ability was found, and the vacuum sintering YAG was also studied. The mechanism of ceramic transparency was preliminarily discussed.
1) in the process of preparing YAG nano powder by ammonium bicarbonate precipitation method, the concentration of the mother salt solution, the drop acceleration of the mother salt solution and the effect of organic solvent on the preparation of YAG nano powder were studied.
(1) the concentration of the mother salt solution has a significant influence on the morphology of the YAG precursor and the calcined powder. Only the precursors generated by the low concentration of the mother salt solution ([Y3+]=0.08M, [Al3+]=0.13M) have good dispersion, and are more favorable for obtaining the homogeneous and nearly spherical YAG nanoparticles. The influence of the phase of YAG nanopowders is not too obvious, but relatively low solubility of the parent salt solution can obtain nano powders with better YAG phase.
(2) the drop acceleration of the mother salt solution is more significant. When the mixture rate of the mother salt solution and the NH4HC03 precipitant solution is faster, the nano powders with better YAG phase are easier to be obtained. And the low concentration of the mother salt solution and the NH4HC03 solution will be easier to obtain the YAG nano powder with better phase. The YAG nanoscale powders have good sintering properties.
(3) a small amount of organic solvent (the volume ratio of organic solvent and mother salt solution is 1:5) has a certain effect on the phase and morphology of YAG nano powders. Adding a small amount of ethanol as a solvent has a good effect on obtaining pure phase YAG nano powder. A small amount of ethanol and a fast mixture of NH4HC03 precipitant solution in the low concentration mother salt solution can obtain the pure phase. YAG nano powder with good particle morphology, so the addition of a small amount of ethanol in the mother salt solution has a certain effect on the preparation of stable YAG nano powders. The YAG powders prepared in the experiment can be sintered transparent ceramics. It is proved that the fine sintered YAG nano powders can be obtained by controlling the above three factors systematically.
2) in the preparation of Nd:YAG nano powders by microwave assisted homogeneous precipitation, the influence of the concentration of the mother salt solution, the amount of urea, the dosage of NH4 2S04 and the aging effect on the preparation of Nd:YAG nano powders were studied.
(1) the influence of the concentration of the reactant mother salt solution, the amount of urea and the dosage of the dispersant (NH4) 2S04 on the properties of the Nd:YAG nano powder should be considered basically. In this experiment, the concentration of the mother salt solution is [Nd3++Y3+]=0.06M, [A13+]=0.1M, the quantity of the substance of the urea and the metal ions is 25:1, the dosage of the dispersant (NH4) 2S04 is the mother salt. 8% of the total nitrate content in the solution is the best value for preparing Nd:YAG nanopowders.
(2) the effect of aging state and aging time on the phase and morphology of Nd:YAG nano powders shows that the aging effect of.Nd:YAG precursor in the reaction kettle is better than that in the air, and it is more beneficial to obtain Nd:YAG nanoparticles with uniform particle size and ellipse shape, but it still needs a certain material exchange during the aging process. The susceptibility of.Nd:YAG precursors to the external environment is shown to be reduced and then increased with the aging time of the precursor in the reaction kettle. In this experiment, the particle size of the Nd:YAG nano powders obtained after the reaction of the reaction of Fu Zhongchen 6 days is the smallest.
(3) the influence of humidity and temperature on the phase and morphology of Nd:YAG nano powder is obvious. Humidity and temperature have a certain dependence on the effect of Nd:YAG nano powder, so the appropriate humidity and temperature must be controlled in the process of preparing Nd:YAG nano powder. The humidity of this experiment is at 30%-50% and temperature at present. Nd:YAG nanoparticles with better properties can be obtained at 25 degrees centigrade.
3) in order to prepare Nd:YAG transparent laser ceramics successfully, the Nd:YAG nanopowders must possess the following properties:
(1) in order to obtain Nd:YAG transparent ceramics, Nd:YAG nanopowders with pure YAG phase must first be prepared.
(2) in order to obtain high quality Nd:YAG nano powders, various factors affecting the properties of Nd:YAG nano powders must be strictly controlled. The prepared Nd:YAG nano powders must have relative stability in physical and chemical properties, and also have certain sintering activity to ensure the successful sintering of Nd:YAG transparent ceramics, so the prepared Nd:Y AG nano powders have smaller size particles, narrower particle size distribution and lower defect density. Such Nd:YAG nano powders will help to obtain good properties of Nd:YAG transparent ceramics.
(3) in addition to the pure YAG phase, the smaller size particles, the narrow particle size distribution and the lower defect density, the Nd:YAG nano powders should also have the uniform microscopic composition and the appropriate offset degree of the stoichiometry. These properties ultimately guarantee the good performance of the Nd:YAG transparent ceramics.
(4) when the temperature is at 25, the humidity is between 30-50%, and the Nd:YAG nanometer powder of 6 days in the reaction kettle is sintered at 1730 C for 6 days. The laser output energy of the fine cast Nd:YAG transparent ceramic sheet is 305 mW and the slope is 5.1%..
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2011
【分類號】：TB383.1

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 楊梨容;劉暢;李小伍;徐藝;魏成富;張林;唐杰;;滴定方式對釔鋁石榴石(YAG)粉末結(jié)構(gòu)及形貌的影響[J];粉末冶金技術(shù);2013年04期

相關(guān)碩士學(xué)位論文 前1條

1 王莉平;上轉(zhuǎn)換納米粒子的制備及其在毒素快速檢測中的應(yīng)用研究[D];湖南師范大學(xué);2012年

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本文編號：1909009