半固态Al-Si合金固液相变液相率的数值分析  

Numerical Analysis of Liquid Fraction in Solid-Liquid Phase Transformation of Semi-Solid Al-Si Alloy

作　　者：王耘涛[1] 袁晓光[2] 于宝义[2] WANG Yun-tao;YUAN Xiao-guang;YU Bao-yi(College of Mechanical Engineering,Inner Mongolia University for the Nationalities,Tongliao 028042,Inner Mongolia,China;School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China)

机构地区：[1]内蒙古民族大学机械工程学院,内蒙古通辽028042 [2]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《铸造》2018年第9期805-809,共5页Foundry

基　　金：国家自然科学基金面上项目(50971092);内蒙古民族大学博士科研项目(BS330)

摘　　要：基于热力学方程,建立了半固态Al-Si合金固液相变液相率的非线性数学模型,并利用高斯-牛顿迭代法进行了数值求解。采用热涵法对过共晶Al-20Si-3Fe-1Mn-4Cu-1Mg合金的固液相变进行了研究,将其用于对所建立模型可靠性的验证并与Scheil公式进行了对比。结果表明,液相率与加热温度的关系不是Scheil公式描述的简单线性增加,在不同的温度区间,液相率的增长速率并不完全一致,液相率随温度升高呈现非线性增加的趋势。所建立的非线性数学模型与试验数据非常吻合,与Scheil线性回归模型相比具有更小的离散度和更高的可信度,基本能够反映半固态Al-Si合金在发生固液相变时液相率与加热温度的关系。The nonlinear mathematical model of liquid fraction in solid-liquid phase transformation of semi-solid A1-Si alloy was established based on the thermodynamic equations, and the numerical solution was obtained by the Gauss-Newton iteration algorithm. The solid-liquid phase transformation of hypereutectic A1-20Si-3Fe-1Mn-4Cu-1Mg alloy was studied by DSC, which was used for the model reliability validation and to compare with the Scheil linear regression model. The results show that the liquid fraction of the semi-solid A1-Si alloy does not increase linearly with the heating temperature, which is not consistent with the Scheil expression; the growth rate of liquid fraction is not the same entirely in different temperature ranges. The nonlinear mathematical model established in the paper fits well with the experimental data, and compared with the Scheil linear regression model, the nonlinear mathematical model has a smaller dispersion and higher credibility. The relationship between liquid fraction and heating temperature of the semi-solid A1-Si alloy can be reflected by the nonlinear mathematical model in the case of solid-liquid phase transformation.

关 键 词：半固态加工 液相率 非线性数学模型 数值分析 

分 类 号：TG111.3[金属学及工艺—物理冶金]