半固态ZL201合金本构关系研究

采用Gleeble 3800热模拟试验机对液相线铸造获得的ZL201合金半固态坯料进行了不同工艺参数下的热模拟试验,并进行了变形抗力本构方程拟合,以此为基础根据Stefan方程确定了幂律模型中的表观粘度等参数.采用商用仿真软件ANYCASTING对汽车发动机支架进行了触变压铸过程数值模拟分析,获得了ZL201合金的半固态充填流动特征响应.结果表明:半固态表观粘度随剪切速率增大而下降,在充型过程中呈现剪切变稀的触变成形特点,半固态浆料将以层流方式充填型腔,可获得充型完好的半固态压铸零件.

Research on the constitutive relationship of semi-solid ZL201 alloy

Thermal simulation compression tests on semi-solid billet of ZL201 alloy prepared by Near-Liquidus-Casting at different parameters were carried out using the Gleeble3800 dynamic material testing machine,and then the constitutive equation of semi-solid ZL201 alloy was established based on the experimental data.According to the constitutive equation and the equations presented by Stefan,parameters of power law model,such as apparent viscosity,were identified.The commercial simulation software ANYCASTING was applied to simulate and analyze the thixotropic die-casting processes of semi-solid automobile engine bracket.The flow characteristic of semi-solid ZL201 alloy in semi-solid die-casting processes was investigated with simulation.The results show that the apparent viscosity decreases with the increase of shear rate,semi-solid alloy shows that shearing thinning thixotropy,the semisolid slurry filled the cavity by way of laminar flow,with the sound semisolid die-casting part obtaining.