稀土对Al-3Ti-0.2C细化剂显微组织及细化性能的影响  

Effects of Rare Earth on Microstructure and Refining Performance of Al-3Ti-0.2C Refiner

作　　者：李苗[1] 孔亚萍[1] 管仁国[2] 翁康荣[1] 赵红亮[1] 

机构地区：[1]郑州大学材料科学与工程学院,河南郑州450002 [2]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《铸造》2011年第5期473-476,共4页Foundry

基　　金：国家自然科学基金重点项目(51034002);国家大学生创新性试验计划项目(101045942)

摘　　要：采用海绵钛、石墨粉、混合稀土及工业纯铝制备了Al-3Ti-0.2C-1RE及Al-3Ti-0.2C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(OM),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Al-3Ti-0.2C相比,Al-3Ti-0.2C-1RE中TiC粒子的数量增多,TiAl3相的尺寸减小,并生成了Ti2Al20Ce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,Al-3Ti-0.2C使晶粒尺寸细化到151μm,而Al-3Ti-0.2C-1RE可将其细化到107μm。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 151 μm and 107 μm,respectively at 0.4% addition level.

关 键 词：AL-TI-C 晶粒细化剂 稀土 细化性能 

分 类 号：TG292[金属学及工艺—铸造]