本文選題：非晶FeW合金鍍層 + 真空擴(kuò)散焊��； 參考：《北京科技大學(xué)》2016年博士論文

【摘要】：核能是一種主要的傳統(tǒng)化石燃料的清潔替代能源。在核能應(yīng)用領(lǐng)域中,材料問題是其能否最終實(shí)現(xiàn)的關(guān)鍵問題之一。核能的主要形式有兩種：核聚變能和核裂變能。在聚變材料中,面向等離子體材料(Plasma Facing Material,PFM)是決定聚變能能否開發(fā)成功的關(guān)鍵材料。其中進(jìn)一步提高PFM的綜合性能和增強(qiáng)PFM與銅基熱沉材料的連接性能是急需解決的兩個(gè)難題。在核裂變領(lǐng)域,壓水堆是世界上最早開發(fā)的動(dòng)力堆堆型,也是目前世界上應(yīng)用最廣泛的裂變反應(yīng)堆堆型。在壓水堆中,材料需要承受高溫高壓以及核反應(yīng)所產(chǎn)生的輻射等。苛刻的服役環(huán)境對材料提出了更高的要求。非晶FeW合金鍍層是一種具有優(yōu)異耐蝕性的功能性合金鍍層,已經(jīng)在工業(yè)領(lǐng)域獲得廣泛的應(yīng)用。同時(shí),非晶FeW合金鍍層也是一種可以用于核能領(lǐng)域的潛在材料。本文從FeW非晶合金鍍層的有序化轉(zhuǎn)變和新功能探索兩方面出發(fā),研究了不同電鍍工藝對非晶合金鍍層的影響；有序化過程中,研究了溫度對鍍層表面形貌、結(jié)構(gòu)、耐蝕性的影響；研究了基于非晶FeW合金鍍層為中間層的異種金屬連接問題：探索研究了非晶鍍層的耐輻照腐蝕行為及表面疏水化改性。具體的研究工作及成果如下：(1)采用直流電鍍工藝和雙脈沖電鍍工藝制備出FeW非晶合金鍍層。采用直流電鍍法時(shí),當(dāng)電流密度增大至0.1 A/cm2時(shí),鍍層顆粒明顯長大,同時(shí)伴隨較淺的凹坑產(chǎn)生;當(dāng)電流密度進(jìn)一步增大至0.5 A/cm2時(shí),鍍層表面顆粒明顯減小,同時(shí)伴隨大量微米孔洞產(chǎn)生。采用脈沖電鍍法時(shí),當(dāng)正向占空比為10%,反向占空比為30%時(shí),獲得了表面相對致密均勻的非晶鍍層。(2)考察了真空條件下,熱處理溫度對鍍層表面形貌、結(jié)構(gòu)、耐蝕性的影響。當(dāng)熱處理溫度為700℃時(shí),FeW合金鍍層完全晶化。當(dāng)熱處理溫度為500℃時(shí),耐蝕性最好。(3)首次提出采用非晶FeW合金鍍層作為中間層,通過真空擴(kuò)散焊接工藝實(shí)現(xiàn)W板和Cu板、W/Cu合金的擴(kuò)散連接。當(dāng)焊接溫度為950 ℃時(shí),焊接界面的抗拉強(qiáng)度大于146 MPa。獲得的新型W/Cu-PFM模塊可承受4 h的短脈沖等離子體的原位輻照。并且利用此工藝已經(jīng)成功的將其模塊放大至100 mm×100 mm,完全滿足偏濾器對實(shí)際模塊的尺寸要求。(4)首次研究了非晶FeW合金鍍層的伽馬輻照腐蝕行為。在輻照的條件下,產(chǎn)生了具有強(qiáng)氧化性的輻照分解產(chǎn)物(如H2O2),因此鍍層中Fe元素和W元素在腐蝕過程中的反應(yīng)路徑有所差別：此外,在輻照條件下測得的腐蝕電位明顯高于未輻照樣品。(5)對均勻多孔的直流鍍層,在經(jīng)過500℃、600℃不同溫度熱處理后,用十七氟癸基三甲氧基硅烷修飾,并獲得粗糙度分別為82.2、117.5,接觸角分別111°±1°、134°±1°的疏水表面。且修飾后所獲得疏水表面的耐蝕性高于未修飾的親水表面。
[Abstract]:Nuclear energy is a major clean alternative to traditional fossil fuels. In the field of nuclear energy application, the material problem is one of the key questions whether it can be finally realized. There are two main forms of nuclear energy: nuclear fusion energy and nuclear fission energy. Plasma Facing material is the key material to determine the successful development of fusion energy in fusion materials. Among them, it is urgent to improve the comprehensive properties of PFM and strengthen the bonding properties of PFM and copper-based heat sink materials. In the field of nuclear fission, PWR is the earliest type of power reactor developed in the world, and it is also the most widely used type of fission reactor in the world. In PWR, materials are subjected to high temperature and high pressure and radiation from nuclear reactions. The harsh service environment puts forward higher requirements for materials. Amorphous FeW alloy coating is a functional alloy coating with excellent corrosion resistance and has been widely used in industrial field. At the same time, amorphous FeW alloy coating is also a potential material for nuclear energy. In this paper, the effect of different electroplating processes on amorphous alloy coating is studied from the aspects of ordering transformation and new function exploration of FeW amorphous alloy coating, and the effect of temperature on the surface morphology and structure of amorphous alloy coating is studied in the process of ordering. The influence of corrosion resistance, the problem of dissimilar metal bonding based on amorphous FeW alloy coating as intermediate layer was studied. The radiation corrosion resistance and surface hydrophobic modification of amorphous FeW alloy coating were investigated. The specific research work and results are as follows: (1) FeW amorphous alloy coating is prepared by DC electroplating and double pulse electroplating. When the current density is increased to 0. 1 A/cm2, the coating particles grow up obviously, and the shallow pits are produced, and when the current density is further increased to 0. 5 A/cm2, the surface particles of the coating decrease obviously. At the same time, it is accompanied by a large number of micron holes. The effect of heat treatment temperature on the surface morphology, structure and corrosion resistance of the coating was investigated under vacuum condition when the positive duty cycle was 10 and the reverse duty cycle was 30. The amorphous coating with relatively dense and uniform surface was obtained under the condition of vacuum. When the heat treatment temperature is 700 鈩，

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