(中国科学院金属研究所, 沈阳110015)
摘 要: Ti-55高温钛合金在缓冷(1000 kg铸锭冒口)条件下，正常凝固区中稀土相呈弥散分布状态，初始补缩区中稀土相聚集成团，正常补缩区中稀土相颗粒沿平行于凝固界面方向规则排列；在快冷(锤砧薄片)条件下， 稀土相除弥散分布在合金中外，出现稀土相颗粒排列成行的现象。两种凝固条件下均出现颗粒规则排列现象的原因是凝固界面的平面长大。
关键字: Ti-55高温钛合金；稀土相；凝固特征
（Institute of Metal Research, The Chinese Academy of Sciences, Shenyang 110015, P.R.China）
Abstract:The solidifies characterization of rare earth-rich phase in slowly and rapidly cooled Ti-55 alloy was observed and analyzed. After the ingot of Ti-55 alloy solidifies slowly, the rare earth-rich phase particles are uniformly distributed in the coarse dendritical matrix within normal solidification zone. However, for the shrinkage area, lots of aggregated particles appear in the initial shrinkage zone, in addition, the particles in the normal shrinkage zone formed bands and are aligned parallel to the advancing solidification front. Rapid solidification produces fine rare earth-rich phase particles, of which some particles are uniformly distributed in the α-Ti matrix, others are lined up to be rows of band. The reason for the formation of the band both in the ingot-riser area and in the rapid solidification flakes is that the advancing liquid-solid interface remains planar.
Key words: Ti-55 high temperature titanium alloy; rare earth-rich phase; solidified characterization
