(1. 蘭州理工大學材料科學與工程學院，蘭州 730050；
2. 蘭州理工大學省部共建有色金屬先進加工與再利用國家重點實驗室，蘭州 730050)
摘 要: 采用超音速等離子噴涂技術在45號鋼基體上預制Ni60合金涂層，利用定向冷卻裝置在不同流量冷卻水條件下，對感應重熔后的涂層進行強制冷卻。通過OM、SEM(EDS)、XRD等手段研究了不同流量冷卻水對感應重熔涂層組織結構的影響。結果表明：隨著冷卻水流量的不斷增大，感應重熔涂層的組織結構發(fā)生了極大改變，涂層與基體之間形成了一條明顯的冶金結合帶；當流量為80 L/h時，涂層中形成的“十字架”形結構的定向凝固組織結構致密細小，對稱性最好，且具有較好的取向一致性；晶粒沿[001]方向的偏離角θ較小，僅在0°~8°之間，而具有高度((200)晶面)擇優(yōu)取向趨勢。
關鍵字: Ni60涂層；感應重熔；強制冷卻；定向凝固組織；擇優(yōu)取向
（1. College of Materials and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
2. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The Ni60 alloy coating was prefabricated on 45 steel substrate by supersonic plasma spraying technology and fasted cooling was then conducted on the coating by directional cooling device under conditions of cooling water at different flux after induction remelting. The effect of cooling rate on the microstructures of the induction remelting coating was investigated by OM, SEM (EDS) and XRD, etc. The results indicate that the microstructures of the coating change greatly and the metallurgical bond forms between the coating and substrate with the increase of flux of the cooling water. When the flux of cooling water is 80 L/h, the directional solidification microstructures of the cross in the coating are dense and fine. The symmetry of the cross is perfect and the orientation of the cross is well consistent. Besides, its deviation angle is small with respect to the [001] direction and the range of deviation angle is 0°-8°. At the same time, it has a highly preferred orientation along the (200) crystallographic plane.
Key words: Ni60 coating; induction remelting; forced cooling; directional solidification microstructure; preferred orientation
