Rheological behavior, microstructue and hardness of A356 aluminum alloy in semisolid state using backward extrusion process
The influence of temperature on the flow behavior and theological characteristics of an A356 alloy in the semi-solid state was investigated using backward extrusion process. Experiments were performed at 5 temperatures and 4 different wall thicknesses. Viscosities were determined using the forcedisplacement graphs obtained form back extrusion tests. As observed experimentally, at a constant temperature, the increase of shear rate results in the decrease of alloy viscosity exponentially. Raising the temperature increases the liquid fraction hence reduces the semisolid alloy viscosity. Metallographic and image analyses show that, because of low forming speed, liquid has time to escape from solid phase forward the sample wall. This condition is the main reason for the segregation phenomenon seen in the base and walls. Vickers hardness test on samples reveals that the hardness increases with the decrease of temperature and wall thickness.
aluminum alloy A356 backward extrusion semisolid forming rheology
S. A. SADOUGH M. R. RAHMANI V. POUYAFAR
Center of Excellence in Termoelasticity, Amir Kabir University of Technology, Tehran, Iran Department of Mechanical Engineering, Islamic Azad University Science and Research Branch,Tehran, Iran
国际会议
北京
英文
906-910
2010-09-16（万方平台首次上网日期，不代表论文的发表时间）