(1. 寶山鋼鐵股份有限公司 寶鋼分公司，上海 201900；
2. 寶山鋼鐵股份有限公司 技術(shù)中心前沿技術(shù)研究所，上海 201900)
摘 要:
采用SEM和TEM對(duì)冷噴涂Ni涂層的微觀組織進(jìn)行表征。結(jié)果表明：在粒子尺寸范圍內(nèi)，Ni涂層的微觀組織有明顯差異：粒子界面處，微觀組織以帶狀晶和等軸晶為主；界面附近以位錯(cuò)墻、位錯(cuò)纏結(jié)形貌為主，且距離界面越近，晶粒細(xì)化越明顯；兩區(qū)域?qū)?yīng)的組織演變機(jī)制分別是高應(yīng)變速率動(dòng)態(tài)再結(jié)晶機(jī)制和位錯(cuò)運(yùn)動(dòng)導(dǎo)致的晶粒細(xì)化機(jī)制。
關(guān)鍵字: Ni涂層；冷噴涂；動(dòng)態(tài)再結(jié)晶；微觀組織
（1. Baosteel Branch, Baoshan Iron and Steel Co. Ltd., Shanghai 201900, China;
2. Advanced Technology Institute, Baosteel Technology Center, Baoshan Iron and Steel Co. Ltd., Shanghai 201900, China）
Abstract: The microstructures of cold-sprayed Ni coating were characterized by SEM and TEM. The results show that the local microstructure in a particle of the cold-sprayed Ni coating reveals a quite inhomogeneous appearance. Elongated grains and equiaxed grains are typical microstructures at the particle-particle interface, while the regions near the interface exhibit heavily deformed appearance with a large number of dislocation walls or dislocation tangles. Moreover, the grain refinement near the interface is more pronounced than that on the periphery of the interface. The main mechanisms for microstructural evolution at, and near the interface are the dynamic recrystallization under high-strain-rate deformation and the plastic strain-induced grain refinement due to dislocation movement, respectively.
Key words: Ni coating; cold spray; dynamic recrystallization; microstructure
