摘要 过共晶Al-Si合金具有很多优异的物理性能，但由于粗晶的存在，影响了整体的性能。本实验制备了新型Al-8Ti-2.5P-0.5C中间合金，经XRD测试，Al-8Ti-2.5P-0.5C是由α-Al，TiAl3、Ti5P3.16相组成。通过FESEM分析Al-Ti-P-C体系中不同生长阶段Ti-P相的典型形貌，确认了可以在Al-Ti-P-C熔体中合成一种新的Ti5P3.16晶体来利用磷诱导Ti-C的相变，其过程是P原子掺杂到Ti-C附聚物中，引发了从Ti-C到Ti-P相的逐渐相变，最终形成了由六个{10-10}面和两个平行{0001}面包围的正六棱柱形态Ti5P3.16晶体。最后探究了Ti5P3.16相对A390合金的初级Si晶粒的改善作用，通过添加1.5％Al-8Ti-2.5P-0.5C中间合金，初级Si的平均尺寸从112μm显着降低到18.4μm，这是由于Si原子诱导Ti-P相的逐渐转变生成许多亚微米Al P颗粒，而Al P在Al-Si熔体的固化过程中提供了初晶Si的直接形核底物。

关键词 Al-8Ti-2.5P-0.5C合金；钛磷化合物；微观组织；细化；变质。

毕业设计说明书外文摘要

Title    Micro structure Characterization and Refining Behavior Titanium Phosphorus Compounds in Aluminum Alloy Melt    

Abstract：HypereutecTi-C Al-Si alloys have many excellent physical properties, but due to the presence of coarse grains, the overall properties are affected. The Al-8Ti-2.5P-0.5C is prepared by XRD, and Al-8Ti-2.5P-0.5C is composed of α-Al, TiAl3 and Ti5P3.16. The typical morphology of Ti-P phase in Al-Ti-PC system at different growth stages was analyzed by FESEM. It was confirmed that a new Ti5P3.16 crystal could be synthesized in Al-Ti-PC melt to induce Ti-C The process is that the P atom is doped into the Ti-C agglomerate, triggering a gradual phase transition from Ti-C to Ti-P phase, and finally formed by six {10-10} faces and two parallel {0001} faces Surrounded by a hexagonal prism form Ti5P3.16 crystal. Finally, the effect of Ti5P3.16 on the primary Si grain of A390 alloy was investigated. The average size of primary Si was significantly reduced from 112μm to 18.4μm by adding 1.5% Al-8Ti-2.5P-0.5C master alloy. As a result of the gradual transformation of the Si-induced Ti-P phase, many submicron AlP parTi-Cles are formed, and AlP provides a direct nucleation substrate for the primary Si during the curing of the Al-Si melt.

Keywords  Al-8Ti-2.5P-0.5C Al-Si alloy; titanium-phosphorus compound; micro- structure;Refinement;Metamorphism.

目   次

1  绪论1

 1.1  引言 1

 1.2 Al-Si合金细化研究现状1

 1.3 选题意义以及研究内容5

 1.3.1 课题选题意义5

 1.3.2 课题研究内容5

 2 实验材料与设备6

2.1 引言 6

2.2 实验材料 6

2.3 实验设备以及实验器材 6

3 实验过程与分析 8

3.1 引言8

3.2 实验过程8

3.3 实验结果及分析8

结论 14

致谢  15

参考文献17

1  绪论

1.1  引言

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