(1.清华大学 力学工程系,北京 100084;
2.清华大学 机械工程系,北京 100084)
摘 要: 对传统的静态剪切流变实验方法进行了改进,研究了不同初生α相形态半固态A356合金的流变规律。通过对实验结果进行分析, 提出用6个特征参数描述半固态A356合金的静态剪切流变特征:加载瞬时切变γ1,卸载瞬时恢复切变γ2,加载过程总切变γ3,卸载稳定状态下的切变γ4,加载时间t1及卸载稳定时间t2。采用回归分析得到流变参数与切变应力、初生α相组织以及固相体积分数之间的关系,为系统评定半固态A356合金的流变行为提供了实验依据。
关键字: A356合金;初生α相;流变行为;静态剪切
A356 alloy with different morphology
of primary α phases
(1.Engineering Mechanics Department, Tsinghua University,
Beijing 100084, China;
2.Mechanical Engineering Department, Tsinghua University,
Beijing 100084,China)
Abstract:Traditional static shear tests were revised so as to study the rheological behavior of semisolid A356 alloy with different microstructure morphology. Sixcharacteristic parameters,consisting of transient shear strain γ1 after loading,transient recovery shear strain γ2 after unloading,total shear strain γ3 during the period of loading,residual shear strain γ4 after unloading,time t1 of loading and time t2 between the initial unloading and the steady state after unloading,were put forward on the basis of analysis of different kinds of rheological curves. T he relations of characteristic parameters to shear stress, morphology of primary α phases, as well as solid fraction were obtained by regression analysis,so that the rheological behavior of semisolid A356 alloy can be evaluated systematically.
Key words: A356 alloy;primary α phase;rheological behavior;static shear