自孕育法流变压铸2024变形铝合金微观组织特征

Microstructure Characteristics of Rheo-diecasting 2024 Wrought Aluminum Alloy Produced by Self-inoculation Method

采用自孕育铸造法制备2024变形铝合金半固态浆料,研究了2024变形铝合金半固态浆料的流变压铸成形,并对半固态浆料和压铸件的微观组织进行研究分析。结果表明,自孕育法可制备出组织均匀细小,具有球形或近球形初生相颗粒的半固态浆料。将自孕育法制备半固态浆料通过短时保温后,浆料中初生α(Al)内部无液相夹裹,平均晶粒尺寸为72.5μm;在增压压力为160 MPa,压射充型速度在2～5 m/s,2024变形铝合金半固态浆料经625℃保温3 min后能顺利进行流变压铸,2024铝合金经流变压铸后铸件的微观组织均匀,且铸件性能良好。

Using a novel of self-inoculation method for preparing the semi-solid slurry of 2024 wrought aluminum alloy,the rheo-diecasting processes for 2024 semi-solid slurry were investigated,the microstructure of the semi-solid slurry and die casting was analyzed.The results indicate that the semi-solid slurry with much finer and uniformer primary phase particles is gained by self-inoculation method.The primary α（Al） phase particles are non-entrapped liquid,and the average equivalent diameter is 72.5 μm when semi-solid slurry is held at the semi-solid range temperature for a short time.When the rheo-diecasting parameters are the pressurization of 160 MPa,the injection speed is in 2～5 m/s and is held at 625 ℃ for 3 min,the rheo-diecasting semi-solid castings with homogeneous microstructure and good properties are obtained.