采用挤压铸造后直接二次重熔的方法制备半固态AZ61镁合金。首先通过挤压铸造预成形铸态AZ61镁合金，以获得细小的枝晶；然后在半固态区间进行二次重熔，细小的枝晶演变成球状晶，完全球化的晶粒被液相均匀包裹。研究结果表明：通过挤压铸造预成形的铸态AZ61镁合金与传统铸造预成形的铸态AZ61镁合金相比，在相同的二次重熔条件下，挤压铸造预成形的铸态AZ61镁合金获得更细小的半固态组织。此外，挤压铸造加上二次重熔触变成形的AZ61镁合金，力学性能优于传统铸造后二次重熔触变成形的AZ61镁合金。%A novel process that combines squeeze casting with partial remelting to obtain AZ61 magnesium alloy with semi-solid microstructures was proposed. In this route, the squeeze casting was used to predeform the magnesium alloy billets to obtain small dendritic structures. During subsequent partial remelting, small dendritic structures transform into globular grains surrounded by liquid films. The results show that the squeeze casting AZ61 alloy after partial remelting produces more ideal, finer semi-solid microstructure compared with as-cast AZ61 alloy treated by the same isothermal holding conditions. Moreover, the mechanical properties of the thixoformed AZ61 alloy prepared by squeeze casting plus partial remelting are better than those of the thixoformed alloy prepared by conventional casting plus partial remelting.
展开▼
