本文選題：鋁化物 + 室溫熔鹽電鍍�。� 參考：《中國(guó)工程物理研究院》2010年碩士論文

【摘要】： 氚對(duì)包容自身的金屬結(jié)構(gòu)材料仍具有高的滲透能力。氚的滲出可產(chǎn)生氚量的損失以及環(huán)境的放射性危害。在氚包容材料表面制備能夠抑制氚滲出的涂層(阻氚層)是減少氚向環(huán)境逃逸的有效措施之一,也是解決ITER(國(guó)際熱核聚變實(shí)驗(yàn)堆)涉氚系統(tǒng)中高溫組件氚滲透問(wèn)題的關(guān)鍵技術(shù)。FeAl/Al2O3鋁化物阻氚層是公認(rèn)具有優(yōu)良阻氚性能與自修復(fù)功能的涂層。然而,目前的涂層制備方法還未能滿(mǎn)足實(shí)用化要求。為此,提出一種新的制備方法：采用室溫熔鹽電鍍鋁方法先在不銹鋼表面制備一定厚度的鋁鍍層,其后通過(guò)熱處理得到富鋁的Fe-Al涂層,最后經(jīng)過(guò)氧化在Fe-Al層表面形成Al2O3膜,并在21-6-9、1Cr18Ni9Ti不銹鋼表面開(kāi)展了涂層的制備工藝、結(jié)構(gòu)和性能研究,取得了較好的結(jié)果。 1.采用AlCl3-EMIC(氯化1-甲基3-乙基咪唑)室溫熔鹽體系在21-6-9鋼上獲得結(jié)合牢固的純鋁電鍍層。鍍層表面光滑、色澤均勻、結(jié)構(gòu)致密,由數(shù)微米大小、均勻分布的等軸狀晶粒生長(zhǎng)而成。鍍前處理、電流密度、電鍍溫度和電鍍時(shí)間的影響程度依次降低：電化學(xué)清洗前處理能顯著提高鍍層結(jié)合強(qiáng)度；鍍層顆粒尺寸隨電流密度、沉積溫度和電鍍時(shí)間增加而增大,但電流密度的影響最為顯著；鍍層總厚度隨電鍍時(shí)間增加呈近似的線性增長(zhǎng)關(guān)系。確定了較優(yōu)的室溫熔鹽電鍍鋁工藝,并在1Cr18Ni9Ti不銹鋼實(shí)物上取得滿(mǎn)意的鍍覆效果。 2.大氣中、650-750℃下通過(guò)1-30h的熱處理,在21-6-9不銹鋼表面形成成分漸變、冶金結(jié)合的Fe-Al涂層。涂層厚度3-30μm,結(jié)構(gòu)致密,雙層或三層結(jié)構(gòu),成分由表面向基體中心逐漸從Al基化合物轉(zhuǎn)變?yōu)镕e基化合物。涂層厚度除與熱處理溫度、熱處理時(shí)間和預(yù)鍍Al層厚度相關(guān)外,還受冷卻速率的影響。大體上,Fe-Al涂層厚度(hFe-Al)與溫度(T)、時(shí)間(t)和Al鍍層厚度(hAl)間的關(guān)系為：hFe-Al=2.39×106t1/2h1/2Al exp[-116900/(RT)]。涂層形成過(guò)程受原子擴(kuò)散控制,分為1)初始Fe-Al合金形成,2)Fe-Al涂層生長(zhǎng)和3)Fe-Al涂層擴(kuò)散退火三個(gè)階段。 3.根據(jù)合金選擇性氧化原理,采用700℃、低氧分壓(Ar、10-2O2)氧化工藝,在21-6-9、1Cr18Ni9Ti不銹鋼Fe-Al涂層表面制得結(jié)合牢固、致密的、100-300nm的Al203膜。最終所制涂層由微米級(jí)厚的FeAl/Fe3Al擴(kuò)散層及納米級(jí)的γ-Al2O3外層組成,層間及界面均無(wú)空洞。較優(yōu)的氧化工藝為Fe-Al涂層700-750℃、10-2O2、Ar中氧化100-200h。 4.在1Cr18Ni8Ti不銹鋼結(jié)構(gòu)容器表面制備的FeAl/Al2O3鋁化物阻氚層外表美觀、結(jié)構(gòu)致密、與基體結(jié)合良好；600-727℃涂層使容器的氘滲透率降低2-3個(gè)數(shù)量級(jí),涂層抗750℃-室溫冷熱循環(huán)10余次。
[Abstract]:Tritium still has high permeability to metal structure materials containing its own. The leakage of tritium can lead to the loss of tritium and the radioactive hazard to the environment. It is one of the effective measures to reduce tritium escape to the environment by preparing a coating (tritium layer) on the surface of tritium containment material that can inhibit tritium exudation. It is also a key technology to solve the tritium permeation problem of high temperature modules in ITER (International Thermonuclear Experimental reactor). Feal / Al _ 2O _ 3 barrier tritium layer is recognized to have excellent tritium resistance performance and self-repair function. However, the current coating preparation methods have not been able to meet the practical requirements. In this paper, a new preparation method is proposed: aluminum coating with a certain thickness is prepared on stainless steel surface by room temperature molten salt electroplating method, then Fe-Al coating with rich aluminum is obtained by heat treatment, and Al _ 2O _ 3 film is formed on Fe-Al layer after oxidation. The preparation process, structure and properties of the coating on the surface of 21-6-9Si 1Cr18Ni9Ti stainless steel have been studied, and good results have been obtained. 1. AlCl3-EMIC (1-methyl-3-ethylimidazolium chloride) room temperature molten salt system was used to obtain solid bonded pure aluminum plating layer on 21-6-9 steel. The surface of the coating is smooth, the color is uniform and the structure is compact, which is formed by the growth of equiaxed grains of several micron size and uniform distribution. The effect of pretreatment, current density, electroplating temperature and electroplating time decreased in turn: the bonding strength of the coating was significantly increased by electrochemical cleaning treatment, and the particle size of the coating increased with the increase of current density, deposition temperature and electroplating time. However, the effect of current density is the most significant, and the total thickness of coating increases linearly with the increase of plating time. The optimum aluminum electroplating process with molten salt at room temperature was determined, and a satisfactory coating effect was obtained on 1Cr18Ni9Ti stainless steel. Fe-Al coating was formed on the surface of 21-6-9 stainless steel by heat treatment at 650-750 鈩，

本文編號(hào)：2003521