Metals and Materials International ( IF 3.3 ) Pub Date : 2021-07-29 , DOI: 10.1007/s12540-021-01011-9 Maoliang Hu 1 , Fei Wang 1 , Bo Jiang 1 , Huasheng Wang 1 , Yile Liu 1 , Zesheng Ji 1
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Abstract
Al–5Ti–1B grain refiner was successfully prepared with the reaction of Ti chips produced during machining and KBF4 in pure aluminum melt. In order to illustrate the reaction mechanism of Ti chips, the effect of different feeding ways and reaction times of Ti chips on microstructure and refining performance of Al–5Ti–1B was systematically investigated by optical microscope, scanning electron microscopy and X-ray diffractometer. The results show that, in three feeding ways, including adding Ti chips firstly, adding KBF4 firstly and adding both Ti chips and KBF4 in the form of prefabricated blocks, the best refining performance of Al–5Ti–1B is the feeding way of using the prefabricated block. TiB2 and TiAl3 as effective heterogeneous nuclei are formed simultaneously around the Ti chips. The average grain size of pure aluminum is refined to about 206.80 μm. The reaction time mainly affects the dissolution process of Ti chips and the average size of TiAl3. With the reaction time from 60 min to 90 min and then to 120 min, the average size of TiAl3 increases from 10.74 μm to 14.30 μm and then to 15.39 μm. During the dissolution process, Ti chips undergo a transition from a thermal isolation layer to a supersaturated zone of Ti atoms. Based on the analysis of the dissolution process of Ti chips, the dissolution model is proposed. Al–5Ti–1B has the best refining performance at 90 min of the reaction time, which can refine pure aluminum to about 223.65 μm.
Graphic Abstract
中文翻译：
加工钛片制备Al-Ti-B晶粒细化剂、纯铝反应机理及晶粒细化性能
摘要
Al-5Ti-1B 晶粒细化剂是利用加工过程中产生的 Ti 碎屑与纯铝熔体中的KBF 4反应成功制备的。为了阐明钛屑的反应机理，采用光学显微镜、扫描电子显微镜和X射线衍射仪系统地研究了不同进料方式和反应时间对Al-5Ti-1B显微组织和细化性能的影响。结果表明，在先加入Ti片、先加入KBF 4和以预制块形式同时加入Ti片和KBF 4三种进料方式中，Al-5Ti-1B的最佳精炼性能为使用预制块。TiB 2和 TiAl 3因为在 Ti 芯片周围同时形成了有效的异质核。纯铝的平均晶粒尺寸细化到约 206.80 μm。反应时间主要影响Ti碎片的溶解过程和TiAl 3的平均尺寸。随着反应时间从 60 分钟到 90 分钟再到 120 分钟，TiAl 3的平均尺寸从 10.74 μm 增加到 14.30 μm，然后增加到 15.39 μm。在溶解过程中，Ti 芯片经历了从热隔离层到 Ti 原子的过饱和区的转变。在分析钛片溶解过程的基础上，提出了溶解模型。Al-5Ti-1B 在反应时间为 90 min 时具有最佳的精炼性能，可将纯铝精炼至 223.65 μm 左右。
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