SOLIDIFICATION AND MICROSEGREGATION BEHAVIORS OF NICKEL-BASE SINGLE CRYSTAL SUPERALLOY SOLIDIFIED AT MEDIUM COOLING RATE

来源期刊：中国有色金属学报(英文版)1998年第1期

论文作者：Du Wei Li Jianguo Fu Hengzhi

文章页码：83 - 87

Key words：single crystal superalloy　cooling rate　microstructure　microsegregation

Abstract: Single crystal blades have already been used in some advanced engines. An industrially valuable nickel-base single crystal superalloy CMSX-2 was solidified at cooling rate from below 1 K/s to 20 K/s. Microstructure and microsegregation were investigated. The results showed that the dendritic arm spacing is highly refined at high cooling rate, the primary dendritic arm spacing can be 35μm, just as 1/10 as that by conventional HRS processing. With the increase of cooling rate, the microsegregation increases and then decreases. In the superfine columnar dendrite, the γ′precipitates are very fine; the amount of γ/γ′eutectic is much fewer and its size is very small.