高温熔体反应法制备Al-5Ti-1B细化剂

Synthesis of Al-5Ti-1B Refiner by Melt Reaction Method

利用高温熔体反应法成功制备Al-5Ti-1B细化剂。通过热力学计算,确定Al-5Ti-1B细化剂的起始反应温度,研究熔体温度对细化剂组织形貌及吸收率的影响。利用X射线衍射,扫描电子显微镜和X射线能谱仪观察细化剂的相组成和形貌,同时对Al-5Ti-1B细化剂铸锭进行高温挤压,并对挤压出的Ф9.5mm丝材进行微观组织分析和细化实验。结果表明:细化剂主要由TiB_2,TiAl_3,α-Al相组成;850℃制备的细化剂铸锭组织形貌最佳,且Ti和B吸收率达到最佳匹配。挤压后TiAl3相呈细小的块状和TiB_2弥散分布在基体内。添加0.2%(质量分数)细化剂后,纯铝的晶粒尺寸由3.99mm细化到0.45mm。

Al-5Ti-1Brefiner was successfully prepared by melt reaction method.Through the thermodynamics calculation,the initial reaction temperature was determined.The influence of reaction temperature on microstructure and absorption rate of the alloy was investigated.The phase and microstructure of the alloy were observed by X-ray diffraction,scanning electron microscope and energy dispersive spectrometer.The Al-5Ti-1Brefiner was extruded at high temperature to wire with the diameter of 9.5mm,and then the refinement experiment was carried out on pure aluminium.The results indicate that the refiner consists of TiB_2,TiAl_3andα-Al,and the microstructure prepared at 850℃is the optimum and the absorption rate of Ti and B matches the best.The TiAl_3 and TiB_2phases distribute homogeneously in the matrix after extrusion.When adding 0.2%（mass fraction）of Al-5Ti-1Brefiner,the grain size of pure aluminium reduces from 3.99 mm to 0.45 mm.