挤压压力对挤压铸造ZL109铝合金组织和性能的影响

Effect of Extrusion Pressure on Microstructure and Properties of Squeezing Casting ZL109 Aluminum Alloy

研究了挤压铸造过程中挤压压力对ZL109过共晶铝合金组织和性能的影响。试验选择在200 t液压机上进行挤压铸造,设计挤压压力为75 MPa、95 MPa、115 MPa进行评估。结果表明,挤压铸造工艺改善了铸件组织,提高了合金的力学性能。挤压压力的变化对合金的初生Si、共晶组织的尺寸、体积分数和力学性能影响显著。在试验范围内,挤压压力为115 MPa下的初生Si颗粒直径相较于75 MPa与95 MPa分别减小了23.5%和28.4%、共晶Si的平均尺寸分别减少了22.1%和50.3%;α-Al的尺寸分别降低了13.6%和18.3%;挤压压力从75 MPa增加到95 MPa,合金的抗拉强度、屈服强度、伸长率和硬度分别提高13.9%、22.6%、19.9%和9.4%;压力从95 MPa提高到115 MPa,抗拉强度和伸长率分别降低2.4%和6.6%。

The effect of squeezing casting pressure on microstructure and mechanical properties of ZL109 hypereutectic aluminum alloy was studied in this paper.The extrusion casting was carried out on a 20-ton hydraulic press machine,and the designed extrusion pressures were 75 MPa,95 MPa and 115 MPa for evaluation,respectively.The results showed that the extrusion casting process improved the microstructure and mechanical properties of the alloy.The change of extrusion pressure had significant effect on the primary Si,eutectic microstructure size,volume fraction and mechanical properties.The results showed that when the extrusion pressure is 115MPa,the primary Si particle diameter decreases by 23.5%and 28.4%compared with 75 MPa and 95 MPa,respectively,and the average size of eutectic Si decreased by 22.1%and 50.3%,respectively.The sizes ofα-Al decreased 13.6%and 18.3%.When the extrusion pressure increased from 75 MPa to 95 MPa,the tensile strength,yield strength,elongation and hardness increased by 13.9%,22.6%,19.9%and 9.4%.When the pressure increased from 95 MPa to 115 MPa,the tensile strength and elongation decreased by 2.4%and 6.6%,respectively.