摘要
采用光学显微镜、扫描电镜及透射电镜研究微量B和Y对铸造Ti-Al-Nb-W合金显微组织的影响。结果表明:Ti-47Al-4Nb-0.6W合金的基本凝固路线为L→β+L→(β+α)+L→(β+α)+γ→α+γ→(α+γL)+γ→(α2+γL)+γ,添加微量B和Y并未改变其基本凝固路径;微量B元素在合金中以短棒状TiB2相存在,细化了铸造Ti-47Al-4Nb-0.6W合金的晶团尺寸及片层间距;微量稀土Y元素主要以Y2O3氧化物颗粒的形式分布于片层晶团界面处,在B和Y的共同作用下,合金的片层晶团尺寸以及片层间距进一步减小。
The effects of trace elements B and Y on the microstructures of cast Ti-Al-Nb-W alloy were investigated by optical microscopy,scanning microscopy and transmission electron microscopy.The results show that the following sequence of phase transformations takes place during the solidification of the Ti-47Al-4Nb-0.6W alloy as： L→β＋L→（β＋α）＋L→（β＋α）＋γ→α＋γ→（α＋γL）＋γ→（α2＋γL）＋γ.The solidification sequence remains unchanged after adding of trace elements B and Y.With the addition of a small amount of element B,the original colony and lamellar sizes of the Ti-47Al-4Nb-0.6W alloy are refined due to the formation of short-stick shaped TiB2 phases.The rare earth element Y is mainly distributed along the boundaries of the colonies in the form of Y2O3 particles.A further refined microstructure can be obtained as a result of the combined effects of elements B and Y.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2011年第4期777-783,共7页
The Chinese Journal of Nonferrous Metals
基金
国家高技术研究发展计划资助项目(2008AA03A233)
中南大学博士后科学基金资助项目(2009-14)
