本文選題：原子層沉積　切入點：羰基鐵粉　出處：《江蘇大學(xué)》2017年碩士論文

【摘要】：原子層沉積(Atomic Layer Deposition,ALD)技術(shù)是一種先進的鍍膜工藝,廣泛應(yīng)用于半導(dǎo)體、微電子等領(lǐng)域,并取得了令人稱贊的效果。但對于超細金屬粉體領(lǐng)域,該技術(shù)的研究還鮮有報道。由于超細金屬粉體較高的表面活性,使得銅粉和鐵粉在高溫、潮濕環(huán)境下易氧化,這將損害材料的多種優(yōu)良性能,所以需要解決在使用過程中的氧化問題。本文旨在通過原子層沉積技術(shù)制備性能優(yōu)異的包覆型金屬粉體材料,提高鐵粉、銅粉的抗氧化性以及改善羰基鐵粉吸波性能,并探索原子層沉積技術(shù)對粉體改性的應(yīng)用前景。主要內(nèi)容如下:(1)本文首次利用原子層沉積技術(shù)對微納米級羰基鐵粉(Carbonyl Iron Powder,CIP)進行表面包覆改性,以三甲基鋁和水為前驅(qū)體,在羰基鐵粉表面生長了無定型氧化鋁薄層,通過調(diào)節(jié)ALD反應(yīng)工藝參數(shù),考察了不同工藝條件對包覆材料的影響,最終確定了適宜的工藝條件。進一步制備了25/50/75個ALD循環(huán)的羰基鐵粉,通過掃描電子顯微鏡以及透射電鏡分析,該氧化鋁薄層致密均勻、與顆粒表面接觸良好,包覆后的材料形貌輪廓清晰可見,顯示出了原子層沉積技術(shù)優(yōu)良的保型性,使用綜合熱分析儀對包覆后的羰基鐵粉進行分析,結(jié)果顯示包覆后的材料具有優(yōu)異的抗氧化性,且隨著包覆圈數(shù)的增加而增強,鹽酸腐蝕實驗表明包覆后的材料具有良好的抗腐蝕性。利用矢量網(wǎng)絡(luò)分析儀等技術(shù)手段系統(tǒng)分析了改性前后羰基鐵粉的電磁性能指標,結(jié)果表明改性后介電常數(shù)減小顯著,磁導(dǎo)率變化相對較小,改善了原羰基鐵粉的電磁參數(shù),提高了材料的阻抗匹配性。(2)首次采用原子層沉積技術(shù),以三甲基鋁和水為前驅(qū)體對微細銅粉進行表面包覆,研究了直接包覆、異丙醇清洗、鹽酸清洗等不同前處理工藝對材料包覆性能的影響。根據(jù)抗氧化性實驗結(jié)果,發(fā)現(xiàn)鹽酸清洗的前處理工藝可以得到熱穩(wěn)定性相對良好的復(fù)合材料,使得氧化起始溫度推遲達110℃左右。通過體積電阻率的測量,發(fā)現(xiàn)包覆后的材料導(dǎo)電性有所減弱。然后進一步討論了不同粒徑銅粉的原子層沉積包覆結(jié)果,結(jié)果顯示小粒徑的材料需要較大的前驅(qū)體壓力才能實現(xiàn)顆粒良好包覆。由于原子層沉積技術(shù)成膜質(zhì)量好、重復(fù)性佳以及厚度精確可控等特點,可以將其應(yīng)用于粉體的改性領(lǐng)域。
[Abstract]:Atomic Layer deposition (ALD) is an advanced coating process, which has been widely used in semiconductor, microelectronics and other fields.However, there are few reports on this technology in the field of ultrafine metal powder.Due to the high surface activity of ultrafine metal powder, copper powder and iron powder can be oxidized easily in high temperature and wet environment, which will damage many excellent properties of materials, so it is necessary to solve the problem of oxidation in the process of application.The purpose of this paper is to improve the oxidation resistance of iron powder and copper powder and to improve the absorbing property of carbonyl iron powder by atomic layer deposition technology, and to explore the application prospect of atomic layer deposition technology in the modification of powder.By adjusting the process parameters of ALD reaction, the effects of different process conditions on the coating materials were investigated, and the appropriate process conditions were finally determined.The carbonyl iron powders of 25-50-75 ALD cycle were further prepared. The results of SEM and TEM analysis showed that the aluminum oxide thin layer was compact and uniform, and it had good contact with the surface of the particles, and the profile of the coating material was clearly visible.The results show that the coated carbonyl iron powder has excellent oxidation resistance and increases with the increase of the number of coating cycles.The corrosion test of hydrochloric acid shows that the coated material has good corrosion resistance.The electromagnetic properties of carbonyl iron powder before and after modification were systematically analyzed by means of vector network analyzer. The results showed that the dielectric constant decreased significantly and the change of magnetic permeability was relatively small after modification, which improved the electromagnetic parameters of the original iron carbonyl powder.The impedance matching property of the material was improved. The atomic layer deposition technique was used for the first time. The surface of fine copper powder was coated with trimethyl aluminum and water for the first time. The direct coating and isopropanol cleaning were studied.Effects of different pretreatment processes such as hydrochloric acid cleaning on coating properties of materials.According to the experimental results of oxidation resistance, it was found that the pretreated process of hydrochloric acid cleaning could obtain composites with relatively good thermal stability, which delayed the starting temperature of oxidation by about 110 鈩，

本文編號：1725945