亚共晶合金晶粒尺寸与相图变量相关双参数模型的检验  

Clarification of two-parameter models for correlating grain size to phase diagram variables in hypoeutectic alloys

作　　者：隋大山 Qing-you HAN Da-shan SUI;Qing-you HAN(Institute of Forming Technology&Equipment,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200030,China;School of Mechanical Engineering,Southeast University,Nanjing 211189,China;School of Engineering Technology,Purdue University,West Lafayette,IN 47906,USA)

机构地区：[1]上海交通大学材料科学与工程学院塑性成形与装备研究院,上海200030 [2]东南大学机械工程学院,南京211189 [3]School of Engineering Technology,Purdue University,West Lafayette,IN 47906,USA

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第6期1721-1733,共13页中国有色金属学报（英文版）

基　　金：supported by the State Key Laboratory of Special Rare Metal Materials,China (No.SKL2021K002)。

摘　　要：提出用于描述晶粒尺寸与工艺条件和相图变量相关联的简单双参数数学模型,然而,这些模型还没有通过良好的实验数据进行充分检验。采用精选的亚共晶合金实验数据检验这些模型,并提出实验数据的选择标准。采用这些双参数模型拟合被选择的实验数据,检查曲线的拟合质量和适用性,从而确定与实验数据吻合更好的数学模型。基于数据分析,探讨溶质元素细化晶粒尺寸的机理。结果表明,晶粒尺寸与合金凝固间隔之间存在明确的依赖关系,这种关系可采用P变量加以描述。晶粒尺寸对凝固间隔的这种明显依赖表明,在充型和凝固过程存在对流的铸锭和铸件中,与枝晶破碎有关的机理是控制溶质元素细化晶粒的主要运行机制。Simple two-parameter models were proposed for correlating grain size to process conditions and phase diagram variables.However,these models have not been fully examined using data obtained from well controlled experiments.This work intended to clarify these models with selected experimental data obtained in dilute hypoeutectic alloys.Criteria for data selected were proposed.The selected experimental data were fitted by these models to examine curve fitting quality and the applicability.Models that fit experimental data better were identified.Mechanisms by which grain size is reduced under the influence of a solute element were examined based on the data analysis.Results suggest that there is a clear dependence of grain size on the solidification interval of an alloy,which can be expressed as the P variable.Such a clear dependence of grain size on solidification interval indicates that mechanisms that are associated with dendrite fragmentation are the dominant operating mechanisms governing grain refinement by solute element in ingots and castings where convection in the molten alloy exists during its mold filling and solidification.

关 键 词：凝固组织 晶粒细化 溶质元素 数学模型 相图变量 晶粒尺寸 亚共晶合金 

分 类 号：TG131[一般工业技术—材料科学与工程]