(1. 江蘇大學(xué) 先進(jìn)制造與現(xiàn)代裝備技術(shù)工程研究院，鎮(zhèn)江 212013;
2. 江蘇大學(xué) 機(jī)械工程學(xué)院，鎮(zhèn)江 212013;
3. 江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013;
4. 中北大學(xué) 材料科學(xué)與工程學(xué)院，太原030051)
摘 要: 利用激光熔覆(Laser cladding, LC)技術(shù)在鎳基高溫合金表層制備NiCoCrAlYSi涂層，隨后利用強(qiáng)流脈沖電子束(High current pulsed electron beam, HCPEB)技術(shù)對(duì)熔覆層表面進(jìn)行輻照處理。利用X射線衍射儀(X-ray diffraction, XRD)、掃描電子顯微鏡(Scanning electron microscopy, SEM)等儀器觀察HCPEB輻照前后激光熔覆層微觀結(jié)構(gòu)演變，并對(duì)比分析熔覆層表面顯微硬度。結(jié)果表明：激光熔覆層主要由γ/γ′相構(gòu)成，表面存在較多孔隙并具有典型的枝晶偏析現(xiàn)象；HCPEB輻照處理后熔覆缺陷消失，表面發(fā)生重熔并形成致密的重熔層，且重熔層厚度隨輻照次數(shù)的增加而逐漸增加。此外，輻照表面誘發(fā)產(chǎn)生交滑移及納米晶結(jié)構(gòu)。表面顯微硬度結(jié)果顯示，HCPEB輻照處理后熔覆層表面硬度顯著高于原始樣品硬度。
關(guān)鍵字: 強(qiáng)流脈沖電子束；激光熔覆；NiCoCrAlYSi涂層；微觀結(jié)構(gòu)；顯微硬度
（1. Engineering Institute of Advanced Manufacturing and Modern Equipment Technology, Jiangsu University, Zhenjiang 212013, China;
2. School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China;
3. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
4. School of Materials Science and Engineering, North University of China, Taiyuan 030051, China）
Abstract:The NiCoCrAlYSi coating was prepared on the surface of nickel-based superalloy by laser cladding(LC) technique, and then was irradiated by high current pulsed electron beam(HCPEB). X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used to compare the microstructure evolution of the laser cladding coating before and after HCPEB irradiation. The surface microhardness of the cladding coating was also analyzed. The microstructural results show that the cladding coating is mainly composed of γ/γ′ phase. Many pores and typical dendritic segregation are found on the surface. After HCPEB treatment, the cladding defects disappear. The surface is remelted, and the thickness of the remelted layer gradually increase with the increase of HCPEB pulses. Besides, the cross-slip and nanocrystalline structures are induced on the irradiated surface. The surface microhardness results show that the surface hardness of the cladding coating after HCPEB treatment is significantly higher than that of the original sample.
Key words: high current pulsed electron beam; laser cladding; NiCoCrAlYSi coating; microstructure; microhardness
