摘要
探讨了AlSi7Cu低压铸造过程中保压压力对其合金微观结构及力学属性的影响。实验发现,在较高的保压压力条件下,制得的AlSi7Cu合金样本展现了更为紧密的微观结构和更圆润的共晶Si颗粒。此外,该条件下合金的充填性能增强,气孔缺陷显著降低,从而使得合金的力学性能得到显著提升。具体而言,在75,150,225 kPa三个不同的保压压力水平下,晶粒尺寸逐步减小,晶粒细化程度相应增加。AlSi7Cu合金的晶粒尺寸及二次枝晶臂间距分别达到了231,182,134μm和43.4,35.9,28.6μm。同时,三个保压压力水平下的密度和孔隙率分别为2.638,2.651,2.670 g/cm^(3)和0.973%,0.807%,0.406%。在力学性能方面,AlSi7Cu合金的抗拉强度、屈服强度和延伸率分别为247.67 MPa,195.68 MPa,4.13%;261.54 MPa,198.80 MPa,5.07%;265.38 MPa,199.31 MPa,7.44%,分别提高了7.15%,1.86%,80.1%。这些数据均表明,提高保压压力可以有效改善合金的微观结构和力学性能。
In this study,the specific effects of these changes on the microstructure of AlSi7Cu alloys and their mechanical properties were investigated by adjusting different levels of holding pressure during the low-pressure casting process.It was found that the fabricated AlSi7Cu alloy samples exhibited a more compact microstructure and more rounded eutectic Si particles under higher holding pressure conditions.In addition,the filling properties of the alloys were enhanced and the porosity defects were significantly reduced under this condition,which led to a significant improvement in the mechanical properties of the alloys.Specifically,a gradual decrease in grain size and a corresponding increase in grain refinement were observed at three different holding pressure levels of 75,150,225 kPa.Specific data showed that the grain size and secondary dendrite arm spacing of the alloys reached 231,182,134μm and 43.4,35.9,28.6μm,respectively.Meanwhile,the density and porosity at the three holding pressure levels were recorded to be 2.638,2.651,2.670 g/cm^(3),and 0.973%,0.807%,and 0.406%,respectively.In terms of mechanical properties,the tensile strength,yield strength and elongation of the AlSi7Cu alloy were reported as 247.67 MPa,195.68 MPa,4.13%;261.54 MPa,198.80 MPa,5.07%;265.38 MPa,199.31 MPa,7.44%,respectively,showing 7.15%,1.86%and 80.1%increases.All these data indicate that increasing the holding pressure can effectively improve the microstructure and mechanical properties of the alloy.
作者
徐通
李勇
王超
薛旭东
XU Tong;LI Yong;WANG Chao;XUE Xudong(Shaanxi Railway Insttitute,Weinan 714000,Shaanxi,China)
出处
《模具技术》
2025年第4期62-67,共6页
Die and Mould Technology
作者简介
徐通,讲师,主要从事低压铸造方面的研究。
