(1. 哈尔滨工业大学 材料科学与工程学院，哈尔滨 150001；
2. 辽宁工程技术大学 材料科学与工程学院，阜新 123000)
摘 要: 研究少量B/TiB2对近β钛合金Ti-B20铸态组织的影响。结果表明：少量的B/TiB2对近β钛合金的铸态组织具有显著的细化作用。添加0.1%B/0.32%TiB2(质量分数)时，细化效果出现拐点，过量的B/TiB2对晶粒细化没有作用。当添加0.3%B/0.96%TiB2(质量分数)时，组织中出现明显的树枝晶形态，这是凝固过程中元素B在枝晶凸起前沿和枝晶臂之间富集的结果。
关键字: 近β钛合金；Ti-B20；晶粒细化；枝晶组织；TiB2
（1. College of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. College of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, China）
Abstract:The effect of trace B/TiB2 on solidification microstructure of near β titanium alloy Ti-B20 was studied. The results show that trace B/TiB2 can refine solidification microstructure of near β titanium alloy remarkably. Inflection point appears when the addition is about 0.1%B/0.32%TiB2 (mass fraction), and more addition of B/TiB2 has no influence on the grain refinement. When the addition is 0.3%B/0.96%TiB2, the obvious dendrite morphology will appear. This is attributed to that the B enriches in the front of the dendrite hump and among the dendritic arms.
Key words: near β titanium alloy; Ti-B20; grain refining; dendrite; TiB2
