Effect of the Pressure on Microstructure of A380 Aluminum Alloy Prepared by Squeeze Casting

摘要

Effects of the solidification pressure on microstructure and mechanical properties of A3 80 alloy have been experimentally investigated. The obtained results show that the microstructures of the A3 80 aluminum alloy is fined, the porosity is decreased and the mechanical properties is improved remarkably with the increase of the solidification pressure. When the squeeze pressure increases from 0 MPa to 75MPa, the size of dendrite arm space decreases from 914 um to 313 μm, reduced by 66%; the eutectic tissue volume fraction increases from 22.5% to 41.36%; the porosity decreases from 4.91% to 1.23%; the secondary dendrite spacing decreases from 39 μm to 18 μm; the size of needle-like p-Al_5FeSi phase decreases significantly, and a few Chinese script a-Fe phases was observed in the grain boundary.