凝固方向对单晶高温合金枝晶组织的影响-IngentaConnect.PDF

67 Influence of the Solidification Directions on Dendritic Structures in a Single Crystal Superalloy , ,, , (, 100081) ZHAN Long-fei,YAN Ping,ZHAO Jing-chen,ZEN Qiang,HAN Feng-kui ( Central Iron and Steel Research Institute, Beijing 100081, China) : , :[ 001] 15, , ; 25, , [011] [ 111] 2 3 , : ; ;; : T 132. 3 : A : 1001-4381(2011) 06-0067-05 Abstract: In order to investigate the effect of solidification direction on dendritic morphology and pr-i mary dendritic arm spacing( PDAS) in N-i based single crystal superalloy, seeding technique was ap- plied to obtain the single crystal samples solidified in different orientations. T he results indicated that when the deviation degrees from solidification direction to [001] orientation were within 15, dendrite morphology kept regular and primary dendritic arm spacing declined with deviation degrees increasing; excessively long secondary dendritic arms blocked the growth of vicinal primary dendritic arm when deviation degrees were up to 25, leading to increase in PDAS. Owing to 2 and 3 dendritic arms orient- ated in preferential growth direction in crystals solidified in [011] and [ 111] orientation respectively, complex dendritic configurations are formed. Key words: N-i based single crystal superalloy; solidification direction; dendritic morphology; primary dendritic arm spacing [001] , , [ 1, 2] [ 10] 0 , , ,, [001] , [3] [ 11] ,