溶质Ti对Al-Ti-B中间合金细化Al影响的新认识:TiB_2粒子的动力学行为及溶质Ti的影响  

A New Understanding Toward Effect of Solute Ti on Grain Refinement of Aluminum by Al-Ti-B Master Alloy:Kinetic Behaviors of TiB_2 Particles and Effect of Solute Ti

作　　者：张丽丽[1] 江鸿翔[1] 赵九洲[1] 李璐[2] 孙倩[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]国家知识产权局专利局专利审查协作天津中心,天津300304

出　　处：《金属学报》2017年第9期1091-1100,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.51501207和51471173;中国载人空间站项目No.TGJZ800-2-RW024;辽宁省自然科学基金项目No.201501043~~

摘　　要：实验研究了Ti添加量对Al-Ti-B中间合金细化工业纯Al晶粒效果的影响,建立了Al熔体中TiB_2粒子动力学行为模型,模拟分析了Al-Ti-B中间合金细化工业纯Al过程中TiB_2粒子的溶解、粗化和快速长大行为及溶质Ti的影响。实验和模拟结果表明,Al-Ti-B中间合金细化工业纯Al过程中,TiB_2粒子的动力学行为对中间合金细化能力的影响不可忽视,溶质Ti能有效抑制Al熔体中TiB_2粒子的溶解、粗化和快速长大行为,影响Al-TiB中间合金的细化能力。Grain refinement may not only promote the formation of a fine quiaxed grain structure, which endows the Al alloy castings with good mechanical properties, but also cause a reduction in the casting defects, such as segregation and hot tearing, which has a dominating effect on the processability of AI alloys. It is, thus, essential for both the cast and wrought AI alloys. Although many techniques, e.g. mechanical vibration, electromagnetic stirring, ultrasound vibration, etc. may be used for the grain refine- ment nowadays, inoculation remains the most widely applied method in the industrial production due to its simplicity and high efficiency. For most AI alloys, Al-Ti-B master alloy is used as the grain refiner. Much work has been done to investigate the solidification behaviors of the AI alloys inoculated with Al-Ti-B master alloys since the 1970 s. Models were developed to describe the microstructure formation underthe effect of inoculants. These researches clearly demonstrate that the grain refining efficiency or the het- erogeneous nucleation rate is closely related to the concentration of solute Ti as well as the number den- sity and size distribution of TiB2 particles in the melt. One shortcoming of the previous research work in this field is that the kinetic behaviors of TiB2 particles during the heating or cooling processes of the melt, Le. dissolution/growth, coarsening and precipitation of TiB2 particles, are neglected. Generally the size distribution of TiB2 particles in the Al-Ti-B master alloy was used in the modeling and simulation of the solidification of AI alloys. In this work, solidification experiments were carried out to investigate the kinetic behaviors of TiB2 particles in the melt and the effect of solute Ti. A model was developed to describe the kinetic behaviors of TiB2 particles during the whole process from the beginning of the addition of TiB2 particles to the melt until the solidification of the melt. Calculations were carried out according to the experiments conditions. The results d

关 键 词：晶粒细化 AL-TI-B中间合金 TIB2 动力学行为 模拟 

分 类 号：TG111.4[金属学及工艺—物理冶金]