中空环形激光熔覆熔池微观组织演变相场法模拟  

Simulation of Micro-Structure of Molten Pool During Hollow Ring Laser Cladding by Phase Field Method

作　　者：谢光耀 王丽芳 罗佳勤 朱刚贤[1] Xie Guangyao;Wang Lifang;Luo Jiaqin;Zhu Gangxian(School of Mechanical and Electrical Engineering,Soochow University,Suzhou 215021,Jiangsu,China;Engineering Training Center,Soochow University,Suzhou 215021,Jiangsu,China)

机构地区：[1]苏州大学机电工程学院,江苏苏州215021 [2]苏州大学工程训练中心,江苏苏州215021

出　　处：《应用激光》2024年第11期12-23,共12页Applied Laser

基　　金：国家自然科学基金(52475523);苏州市科技计划项目(SYC2022143)。

摘　　要：目的熔覆层的性能很大程度上由熔覆层微观组织的结构决定,为探索中空环形激光熔覆层的微观组织结构,通过宏观-微观建模和模拟,研究中空环形激光熔覆IN718过程中熔池的枝晶生长规律,为激光内送粉熔覆层微观组织结构分布规律提供指导。方法采用ansys软件计算中空环形激光熔覆过程中熔池的温度场结果,使用微观组织动态生长条件模型将温度场结果进行转化,把转化的结果带入用matlab建模的微观组织演变的相场法模型中。得到中空环形激光熔覆过程中微观组织演变的模拟结果,最后进行实验验证。结果中空环形激光熔覆IN718合金过程中熔池的凝固过程为柱状晶生长,其生长阶段分别为线性生长、界面失稳、竞争生长和稳定生长。结论随着凝固进行,最先凝固的固相区域的浓度处于最低,随后形成的固相浓度不断增大。枝晶生长进入界面失稳阶段时,在扩散界面上会产生大量的晶核,此时这些初始的柱状晶间距为1.202μm,柱状晶间距在凝固结束时达到最大值,为8.307μm。Objective The performance of a cladding layer is significantly influenced by its microstructure.This study investigates the microstructure of a hollow ring laser cladding layer by examining the dendrite growth of IN718 alloy through macro-microscopic modeling and simulation,providing insights into the microstructural distribution of laser internal powder cladding layers.Methods Ansys software was used to calculate the temperature field results of the molten pool in the process of hollow ring laser cladding.The temperature field results were transformed by using the dynamic growth condition model of micro-structure,and the transformation results were put into the phase field model of micro-structure evolution modeled by MATLAB.The simulation results of micro-structure evolution in the process of hollow ring laser cladding are obtained and verified by experiments.Results In the process of hollow ring laser cladding IN718 alloy,the solidification process of molten pool is columnar crystal growth.The growth stages are linear growth,interface instability,competitive growth and stable growth.Conclusion With the solidification process,the concentration of the first solidified solid phase region is at the lowest,and the concentration of the later formed solid phase is increasing.When the dendrite growth enters the phase of interfacial instability,a large number of crystal nuclei will be generated at the diffusion interface.At this time,the initial columnar grains spacing is 1.202μm,The columnar spacing reaches the maximum at the end of solidification is 8.307μm.

关 键 词：相场法 微观组织 中空环形激光 镍基合金 

分 类 号：TN249[电子电信—物理电子学]