本文關(guān)鍵詞：溶膠—凝膠法制備等離子噴涂涂層封孔層的研究　出處：《武漢理工大學》2010年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 溶膠-凝膠法 封孔劑 耐腐蝕性能 耐高溫氧化性 防污性

【摘要】： 等離子噴涂技術(shù)具有涂層形成速度快、可噴涂材料廣、涂層性能良好、適用范圍廣、成本低等優(yōu)點而在材料表面工程方面獲得了廣泛的應(yīng)用。但由于其自身固有的性質(zhì),使其涂層不可避免的具有孔隙的存在,孔隙的存在會使涂層的耐腐蝕性能下降,因此為了提高涂層的耐腐蝕性能必須對涂層進行封孔處理。封孔處理的方法很多,其中采用封孔劑進行封孔處理應(yīng)用較為廣泛。通常采用微晶石蠟、乙烯樹脂等有機封孔劑進行封孔,但由于其耐熱性差、具有揮發(fā)性和可燃性、對環(huán)保不利等缺點,應(yīng)用范圍受到了限制,所以近年來無機封孔劑的研究正在不斷發(fā)展。 本文采用溶膠-凝膠法研制了一種新型的Si02-Al203溶膠封孔劑,用浸漬-提拉法對等離子噴涂涂層進行了封孔處理。應(yīng)用XRD、FTIR、TG-DTA和SEM等測試手段對封孔層的結(jié)構(gòu)、熱穩(wěn)定性和形貌等進行了表征,采用全浸泡腐蝕試驗、耐高溫氧化試驗及接觸角測試等對涂層的耐腐蝕性能、耐高溫性能及防污性能進行了分析研究。 經(jīng)測試得,研制的新型SiO2-Al203無機非晶態(tài)溶膠封孔劑具有良好的熱穩(wěn)定性。封孔處理前后的SEM照片及孔隙率測試表明,封孔后涂層的孔隙率得到了明顯的降低,并且涂層的致密性得到了顯著提高；涂層斷面的SEM及元素面分布分析顯示,所制備的Si02-Al203封孔劑具有極好的浸滲性和封孔能力。封孔前后的耐腐蝕對比實驗表明,封孔后涂層的耐酸、堿和鹽腐蝕的性能均提高了50%以上,從而增強了涂層對基體的保護作用。耐高溫氧化測試結(jié)果表明,經(jīng)封孔處理后試樣在500℃下的耐高溫氧化性能得到了較大提高。 接觸角測試結(jié)果表明,無機封孔劑封孔處理后涂層對水的接觸角為83.8°,無機-有機復(fù)合封孔后涂層對水的接觸角為101°,故經(jīng)復(fù)合封孔處理后的涂層能夠起到較好的防污作用。腐蝕試驗結(jié)果表明,無機-有機復(fù)合封孔處理后試樣的耐腐蝕性能比無機封孔試樣又提高了27%以上,說明復(fù)合封孔層不僅可以降低涂層的表面能,起到防污作用,而且可以對無機封孔劑未完全封好的孔隙起到進一步的封孔作用。
[Abstract]:Plasma spraying technology has the advantages of fast coating forming speed, wide spraying material, good coating performance and wide application range. Because of its low cost and other advantages, it has been widely used in material surface engineering. However, due to its inherent properties, the coating inevitably has pores. In order to improve the corrosion resistance of coatings, it is necessary to seal the pores of the coatings. There are many ways to seal the coatings. The microcrystalline wax, ethylene resin and other organic sealing agents are usually used to seal the pores, but they are volatile and flammable because of their poor heat resistance. Due to the disadvantage of environmental protection, the application scope is limited, so the research of inorganic sealing agent is developing continuously in recent years. A new Si02-Al203 sol sealing agent was developed by sol-gel method. The plasma sprayed coating was treated by impregnation and Czochralski method. The structure, thermal stability and morphology of the sealing layer were characterized by TG-DTA and SEM. The corrosion resistance, high temperature resistance and antifouling performance of the coatings were studied by oxidation resistance test and contact angle test. The new SiO2-Al203 inorganic amorphous sol sealing agent has good thermal stability. The SEM photos and porosity tests before and after sealing treatment show that the new type of inorganic amorphous sol sealing agent has good thermal stability. After sealing the pores, the porosity of the coating is obviously reduced, and the compactness of the coating is improved significantly. The SEM of the coating section and the distribution of the element surface show that the prepared Si02-Al203 sealing agent has excellent infiltration and sealing ability. The corrosion resistance of the coating before and after sealing is compared with that before and after sealing. The acid, alkali and salt corrosion resistance of the coating was improved by more than 50%, which enhanced the protective effect of the coating on the substrate. The high temperature oxidation resistance of the samples treated by sealing holes at 500 鈩，

本文編號：1439570