(1. 江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013； 2. 江蘇大學(xué) 先進制造與現(xiàn)代裝備技術(shù)工程研究院，鎮(zhèn)江 212013)
摘 要: 利用強流脈沖電子束技術(shù)(HCPEB)對大氣等離子噴涂(APS)CoCrAlY 涂層表面進行輻照處理，對HCPEB誘發(fā)的微觀結(jié)構(gòu)進行詳細(xì)表征，并考察HCPEB處理前后樣品表面在1050 ℃混合鹽Na2SO4/NaCl(質(zhì)量比3:1)條件下的抗熱腐蝕性能。結(jié)果表明：HCPEB輻照后原始涂層表面熱噴涂結(jié)構(gòu)缺陷消失，表面發(fā)生重熔，形成連續(xù)的鼓包狀結(jié)構(gòu)，且隨著輻照次數(shù)的增加，重熔層厚度和鼓包狀結(jié)構(gòu)的尺寸逐漸增加。30次輻照處理后涂層表面形成大量的Y富集Al2O3顆粒和超細(xì)晶結(jié)構(gòu)。熱腐蝕試驗結(jié)果表明，原始涂層抗熱腐蝕性能較差，熱腐蝕20 h后腐蝕產(chǎn)物發(fā)生散裂，腐蝕層深度可到20 μm，且涂層內(nèi)部存在嚴(yán)重的內(nèi)氧化和硫化。相比之下，經(jīng)輻照處理涂層的腐蝕層深度僅有幾個微米，且相對較為連續(xù)致密。HCPEB輻照帶來的輻照效應(yīng)促進熱腐蝕過程中涂層表面保護性氧化膜的快速形成，有效阻擋熔鹽的侵蝕，顯著提高CoCrAlY涂層的抗熱腐蝕性能。
關(guān)鍵字: CoCrAlY涂層；強流脈沖電子束；微觀結(jié)構(gòu)；抗熱腐蝕性能
（1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China; 2. Institute of Advanced Manufacturing and Modern Equipment Technical, Jiangsu University, Zhenjiang 212013, China）
Abstract:High-current pulsed electron beam(HCPEB)treatment was conducted on CoCrAlY coatings prepared by air plasma sprayed(APS)technology. The microstructural evolutions and hot corrosion properties of CoCrAlY coating performed in Na2SO4/NaCl(mass ratio of 3:1)mixture at 1050 ℃ in static air before and after HCPEB irradiation were analyzed in detail. Microstructural observations reveal that after HCPEB irradiation, the coating surface is melted with thermal sprayed defects disappearing, and the modified surface is significantly changed as interconnected bulged nodules with a compact appearance. With the increment of irradiated pulses, the thickness of the remelted layer and the size of the bulged structures were gradually increase. Moreover, abundant Y-rich Al2O3 particulates and ultrafine grains are formed on the top surface after 30-pulsed HCPEB irradiation. The result of hot corrosion test shows that the initial sample has a poor hot corrosion resistance. The depth of corrosion layer reaches to 20 μm, which existes many microcracks inside after hot corrosion for 20 h. Also aggressive internal oxidation and sulfurization are observed. By contrast, the corrosion layer of the irradiated coating was relatively compact and continuous, the depth of which is only a few microns. During the process of hot corrosion, the protective oxide layer is promoted to form immediately due to HCPEB irradiated effects, which can effectively stop off the reactions with molten salt. The results indicate that the hot corrosion resistance of CoCrAlY coatings irradiated by HCPEB treatment is improved dramatically.
Key words: CoCrAIY coating; high-current pulsed electron beam; microstructure; hot corrosion resistance
