Semi-solid A356 Aluminum Alloy Slurry Prepared By LAO Method And Three-dimensional Reconstruction

This research used LAO semi-solid slurry preparation technology and equipment to prepare semi-solid A356 aluminum alloy slurry. The effects of pouring temperature, oscillation amplitude and oscillation frequency on the microstructure of slurry are analyzed, and the two-dimensional metallographic organization is researched in quantitative and distribution. Based on three-dimensional reconstruction technology of serial section means, we obtain the three-dimensional shape of semi-solid A356 aluminum alloy slurry when the pouring temperature are 620 ? and 650 ? respectively, oscillation frequency is 0.75 Hz, oscillation amplitude is 4?. A quantitative study is carried out.Two-dimensional quantitative analysis shows that with the increase of pouring temperature, the yield of the primary alpha(Al) grain diameter increases gradually, the shape factor is on the decline, when the pouring temperature is higher than 640 ?, no matter how the other process parameters change, most of the primary phase is dendrite, when the pouring temperature is below 640 ?, the most of primary phase is nearly spherical. 620-630 ? is the best pouring temperature range. When the pouring temperature is below 650 ? and the oscillation frequency is lower than 0.5 Hz, the alloy melt can form the solidified shell in the tube, when the oscillation frequency is higher than 0.5 Hz, with the increase of oscillation frequency, grain size is refinement, 0.75 to 1.5 Hz is best oscillation frequency range. When oscillation amplitude is less than ?/2, whatever other parameters change, the alloy melt can form the solidified shell in the tube.2?to4? is a reasonable oscillation amplitude range. When pouring temperature is 620 ?, oscillation amplitude is 4?, oscillation frequency is 0.75 Hz, the two-dimensional microstructure of semi-solid A356 aluminum alloy slurry is best, the diameter is 69.00 ?m, shape factor is 0.627.Based on the method of serial section three-dimensional reconstruction technology,we reconstruct a single sperulite and a single dendrite, and carry on the quantitative analysis of equivalent diameter and shape factor of single spherical 52.48 ?m and 0.860, respectively, for the two-dimensional grain has a value of 59.30?m and 0.920, so they have bigger difference showing that the two-dimensional metallographic can't accurate representation space of the grain morphology and parameters. This reserch constructs the three-dimensional morphology of the microstructure of semi-solid A356 aluminum alloy slurry under different process parameters and analysis the consequence. The consequence is consistent with the two-dimensional.