3003 And 3004 Aluminum Alloy Fine Grain Aluminum Ingot Casting And Mechanical Properties Study

It is the crucial for the properties of aluminum alloys that the grain refinement of the alloys, and titanium is the key refining element in the aluminum alloys. It has many advantages that Grain-refining aluminum ingot (GRAI) with low titanium content is used to refine grain of aluminum alloys. In this case, microstructures and properties of 3003 and 3004 aluminum alloys that are melted by GRAI are investigated, and 3003 aluminum alloys that are melted by GRAI with different cerium-rich mixtures of rare earth(RE) contents and homogenization of the alloys are investigated further. The results are as following:(1) The grain of the 3003 aluminum alloys that are melted by GRAI, 3003 aluminum alloys added Ti by Al-5Ti-1B and Al-5Ti master alloy gradually become smaller with the increase of Ti contents. The refinement efficiency of Al-5Ti master alloy is the worst and that of rod-shaped Al-5Ti-1B master alloy is the best when the Ti contents are the same. The refining efficiency of GRAI+Al-10RE and GRAI+Al-10RE+Al-5B is better than GRAI.(2) The precipitated phases and the second dendrite arm spacing are distinctly changed with the increase of RE from 0 to 0.3% in the 3003 aluminum alloys that are melted by GRAI. The precipitated phases have been obviously spheroidized, and the second dendrite arm spacing is the smallest when the RE contents is at 0.25%.(3) The 3003 aluminum alloys that are melted by GRAI are homogenized at 610℃for 0-7h. With the increase of holding time, the precipitated phases much more centralize on the grain boundary. The average diameter and the volume fraction of precipitated phases achieve the smallest values, and the roundness attains the biggest values when the holding time is 6h. So the best homogenization regime is 610℃for 7h.(4) The mechanical properties of as-cast 3003 aluminum alloys added Ti by GRAI are the best, especially its elongation is markedly higher than that added Ti by Al-10Ti master alloy and Al-5Ti-1B master alloy. After homogenization, the elongation of alloys added Ti by GRAI is a little lower than that added Ti by Al-10Ti master alloy, but higher than that added Ti by Al-5Ti-1B master alloy. The mechanical properties of 3003 aluminum foil that are melted by GRAI are similar to the foil added Ti by Al-5Ti-1B master alloy, but better than that added Ti by Al-10Ti master alloy. Morphologies and distribution of the precipitated phases of 3003 aluminum foil added Ti by GRAI and Al-5Ti-1B master alloy are similar, most of them are regular block.(5) The mechanical properties of as-cast 3004 alloys added Ti by GRAI are better than the alloys added Ti by Al-5Ti-1B, but worse than that added Ti by Al-10Ti in state, After homogenization, the mechanical properties of the 3004 Al alloys added Ti by GRAI is similar to the alloys added Ti by Al-5Ti-1B master alloy, but lower than that added Ti by Al-10Ti master alloy. The mechanical properties of 3004 aluminum foil that are melted by GRAI are better than the alloys added Ti by Al-5Ti-1B master alloy and Al-10Ti master alloy. The precipitated phases of 3004 foil that are melted by Ti addition of GRAI are more uniform distribution, most of them are regular block, but the morphologies of the precipitated phases are irregularity, and distribution is zonal in 3004 aluminum foil added Ti by Al-10Ti or Al-5Ti-1B master alloy.