Research On The Al₃Ti Evolution Of Behavior In Aluminum Melt And Refining Performance

The inherent properties of the material depends on the properties and tissue. The most direct way to improve the performance of the material is to change the organizational structure of the material. The most effective and commonly used method to change the organizational structure of aluminum and aluminum alloys is grain refinement. And add refiner is the most direct way to refine the grain. However, people is still no consensus about refinement mechanism of intermediate alloy so far. Grain refinement mechanism of aluminum and its alloys are complex and are still in the exploration and development stage. So there are many issues that need to solve.Research on the evolution of microstructure of Al3Ti in aluminum melt and refining performance by remelting the master alloys of Al-Ti-C and Al-Ti-B at the temperature of730℃and1000℃. The results show that:there is a little effect on the morphology and size about the refinement phase Al3Ti,TiB2and TiC of the master alloy organizaion after remelting at the temperature of730℃.But there is a great influence on the distribution of TiB2and TiC particles. A large gathering at the grain boundaries and existing as the the formation of TiC, TiB2particle group.However there is a great influence on the form of AI3Ti after remelting at the temperature of1000℃and becomes elongated and needles.Also the size of AI3Ti increased with the extension of the holding time. But there is a little influence on the morphology of the particles TiC and TiB2and also there is a great influence on the distribution of TiB2and TiC particles. A large gathering at the grain boundaries and existing as the the formation of TiC, TiB2particle group. Similarly, we also found that:After-remelting master alloys are still have good refining effect for aluminum,there is a little difference between front-remelting alloys.So the organization of master alloys exhibit good stability and long-term nature in the remelting process.We prepared Al-Ti master alloys containing Al3Ti of different shape and size by Melt Thermal Explosion Method and do research on the refinement of these Al-Ti master alloys for pure aluminum.The result shows that:as long as the reasonable control of experimental parameters:the melt reaction temperature and the cooling rate.we can get Al-Ti master alloys containing Al3Ti of different shape and size.Such as for blocky,strip and acicular particles. The melt temperature have absolute influence for the shape and size of Al3Ti.It is good for Larger dimensions of TiAl3with the extension of holding time.It have some effect on the shape and size of AI3Ti of cooling rate. The result also shows that the direct reason for the refinement recession is the reducing of Al3Ti as particle nucleation.The root reason of the reducing of Al3Ti as heterogeneous nucleation particles is the dissolve of Al3Ti phase and making the nucleation rate decreased. But the experiment can not be excluded the reason of Al3Ti precipitation caused refinement recession.