Investigation on Hot Deformation Behavior of Spray Formed Al-7Si-0.5Cu-0.5Mg Alloy

doi:10.3901/JME.2018.14.107

Abstract

Abstract: Hypoeutectic Al-Si alloy is widely used in aviation, aerospace, military and automobile industry because of its notable properties, such as light weight, good corrosion resistance, high specific strength and excellent mechanical properties. The spray deposition technology is used for the fabrication of hypoeutectic Al-7Si-0.5Cu-0.5Mg alloy. The hot deformation behavior of spray formed Al-7Si-0.5Cu-0.5Mg alloy is investigateded by high temperature compression tests as well as microstructural analysis. Results showed that the constitutive equation of Al-7Si-0.5Cu-0.5Mg alloy is established by hyperbolic-sine equation, and the rheological behavior of the alloy is well demonstrated. The deposited alloy was composed of Al, Si, Al₂Cu and Mg₂Si phases. The average size of Si phase is around 8.5 μm. As the strain rate reduced from 1 s^-1 to 0.001 s^-1, the compressive stress of the alloy decreased from 112.19 MPa to 61.26 MPa at the temperature of 300℃. With the deformation temperature increase from 300℃ to 450℃, the flow stress of the alloy reduce from 61.26 MPa to 21.35 MPa with the strain rate of 0.001 s^-1. An adequate deformation time and a high soften degree of Al matrix occurred when the alloy deforme at a low strain rate (0.001 s^-1) and a relative high temperature (450℃). Accordingly, the alloy exhibited increased size of Si phase, which is negative for improving the mechanical properties of the alloy. The optimal deformation temperature and the strain rate are 400℃ and 0.01 s^-1, respectively.

Key words: Al-7Si-0.5Cu-0.5Mg alloy, hot compression, hyperbolic-sine equation, spray forming

CLC Number:

TG146

ZHENG Huijin, PENG Yun, YAN Lu, ZHU Ruofan. Investigation on Hot Deformation Behavior of Spray Formed Al-7Si-0.5Cu-0.5Mg Alloy[J]. Journal of Mechanical Engineering, 2018, 54(14): 107-115.

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