Preparation Of Al-5Ti-1B-Ce Refiner And Refining Performance Research

Adding the homogeneous fine grain refiner master alloys into aluminumalloys can obtain high-quality aluminum alloys.The rare earth added into the Al-5Ti-1B master alloys can effectively eliminate the TiB₂particle size distributionof precipitation and aggregation of particles TiAl₃.The rare earth can improve theability of Al-5Ti-1B master alloys.The Al-5Ti-1B-Ce master alloys was prepared with K₂TiF₆, KBF4and A1-20Ce. The influence of rare earth contents on the Al-5Ti-1B-Ce alloymicrostructure and the influence of the pure aluminum and Al-Si alloy refined byAl-5Ti-1B-Ce was studied by optical microscopy, X-ray diffraction, scanningelectron microscopy. The second phase particles of the Al-5Ti-1B-Ce masteralloys are TiAl₃, TiB₂and Ti₂Al₂₀Ce. Ti₂Al₂₀Ce phase is generated by reactionwith rare earth and TiAl₃. And Ti₂Al₂₀Ce phase which is formed by RE element issoluble when it is added to the aluminum melt during refining process, and itcould not only decompose and produce solute Ti and Ce atoms, but itself act asparticle nucleation. The size of generated second phase TiAl₃decreased with thecontent of rare earth increased, and becamed more uniform distribution. Rareearth changed the viscosity of the molten aluminum, slowing the speed of thesecond phase particles sinking, eliminating the precipitation phenomenon of TiB₂.With prolonged continuous melting Ti₂Al₂₀Ce refiner refined time and improvethe long-term thinning of Al-5Ti-1B-Ce master alloys refiner.Use self-made Al-5Ti-1B-Ce master alloys to refine the industrial aluminumand Al-Si alloys. And study the effects of different rare earth content and holdingtime under different conditions on aluminum and Al-Si alloy chemicalcomposition and microstructure. The size of the pure aluminum decreased firstand then grew up with thinning time, the sample with the smallest grain size at30min. When the thinning time was60min, the refiner appeared recession phenomenon. Al-5Ti-1B-Ce master alloys had a certain refinement effect on Al-Si alloys. Thinning effect increased first and then decreased during the refining.Al-5Ti-1B-2.0Ce master alloys had begined to refine at10min, and the size ofthe grain had grew at30min, and the recession of refinement had appeared at50min. The refining effect of Al-5Ti-1B-3.0Ce master alloys had been not obvious,and the size of the grain had been refined at30min, and the recession ofrefinement has not appeared at50min.