The critical effect of Fe on the grain refinement of aluminium via Al-5Ti-1B addition

4th International Conference on Advances in Solidification Processes

材料科学;物理学

Zhang, Y.^1 ; Ma, N.^1

School of Materials Science and Engineering, Shanghai Jiao Tong University, Dongchuan Road, 800, Shanghai

200240, China^1

关键词: Addition of Al;    Critical effects;    Fine equiaxed grains;    Grain refinement mechanism;    Grain size;    High purity aluminiums;    Ti atoms;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/117/1/012005/pdf
DOI  :  10.1088/1757-899X/117/1/012005

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The influence of Fe on the nucleation potency of TiB2particles was investigated by employing grain refinement of high purity aluminium in this study. Experiment results showed that without Fe, high purity aluminium cannot be refined by 0.8wt.% addition of Al-5Ti-1B. However, high purity aluminium containing 0.08wt.% Fe can be refined effectively by 0.2wt.% addition of Al-5Ti-1B, its grain size was about 206μm in diameter. Fine equiaxed grains of about 153μm in diameter can be obtained for high purity aluminium containing 0.08wt.% Fe and 0.006wt.% Ti. Grain refinement mechanism should include nucleation and dendrite remelting and multiplication. Both nucleation and dendrite remelting and multiplication played essential role on the grain refinement of aluminium. The effect of Fe was linked to increase active nuclei by segregation on TiB2surface and then to promote nucleation of α-Al. The performance of Ti was to enhance the dendrite remelting and multiplication by forming small conglomeration zones of Ti atoms concentrated around TiB2particles.