Al-3Ti-0.2C-1RE and Al-3Ti-0.2C refiners were prepared using Ti sponge, graphite powder, mixed rare earths (RE) and commercial pure aluminium.And the refining experiments were taken by adding the refiner into the commercial pure aluminum.The phase composition and microstructure of the refiners and the microstructure of the samples after refinement were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) with X-ray energy-dispersive spectrum (EDS) and optical microscopy (OM).The results show that the number of TiC phase in the Al-3Ti-0.2C-1RE is increased, the length of TiAl3 is decreased, and Ti2Al20Ce phase is found compared with Al-3Ti-0.2C.During the preparing process of Al-3Ti-0.2C-1RE, the RE atoms tend to congregate on the surface of graphite particles, and eliminate the oxide layer between graphite and melt, which promotes the synthesis of TiC particles.The reaction between Ti2Al20Ce and graphite can also produce TiC.In case of Al-3Ti-0.2C and Al-3Ti-0.2C-1RE refiners, the grain sizes of commercial pure aluminum obtained are 151μm and 107μm, respectively at 0.4％ addition level.%采用海绵铁、石墨粉、混合稀土及工业纯铝制备了A1-3Ti-0.2C-IRE及AI-M-01C两种细化剂,并对工业纯铝进行了细化试验.利用X射线衍射仪(XRD)、带有能谱分析(EDS)的扫描电子显微镜(SEM)及光学显微镜((0m),对细化剂的相组成和显微组织及细化后的组织进行了研究.结果表明,与AI-M-01C相比,Al-3T1A2CA RE中Tic粒子的数量增多,TiAl3相的尺寸减小,并生成了Ti班1求e相.在细化剂的制备过程中,稀土元素富集在石墨颗粒周围,清除石墨颗粒与熔体界面上的氧化膜,促进了Tic粒子的合成.同时部分Ti2Al20Ce相与石墨反应也生成Tic粒子.在工业纯铝中分别添加0.4%的两种细化剂后,AI-M-0.2C使晶粒尺寸细化到151μm,而Al-3Ti-0.2C-1RE可将其细化到107μm.
展开▼
