半固态A356铝合金浆料的充填行为及组织分布

Filling ability of semi-solid A356 aluminum alloy slurry and microstructure distribution

采用流变压铸方法研究了低过热度浇注和弱电磁搅拌制备的半固态A356铝合金浆料的充填行为和组织分布,结果表明：采用该技术制备的半固态A356铝合金浆料,其组织形态优良,经过感应均热后,浆料内部的温度场分布均匀,初生α-Al晶粒更圆整．半固态A356铝合金的浆料温度、压射比压和冲头速度对浆料的充填行为有较大的影响．较高的浆料温度、压射比压和冲头速度都有利于半固态铝合金浆料的充填．在本文的实验条件下,合适的浆料温度为585～595℃,压射比压为15～25 MPa,冲头速度为0．072～0．12m/s．得到的流变压铸件的组织分布均匀,无明显的固液相偏析．

The filling ability of semi-solid A356 aluminum alloy slurry prepared by low superheating pouring and meanwhile electromagnetic stirring at a low power for a short time and the microstructure distribution in the rheo-diecast castings were investigated. The results show that the spherical primary α-Al grains are fine and the temperature distribution is uniform in the prepared slurries. Also the results indicate that the slurry temperature, the injection pressure and piston velocity have important effect on the filling ability of the prepared slurries, the higher slurry temperature, inject pressure and piston velocity are advantageous to the filling ability, the appropriate slurry temperature, inject pressure and piston velocity in this experiment are in the range of 585-595 ℃, 15-25 MPa and 0.072-0.12 m/s respectively. Morever the microstructure of the die castings is homogeneous and no obvious segregation is found.