电弧增材制造金属多晶结构建模及激光超声检测仿真研究

Modeling of Polycrystalline Structure of Arc Additive Manufacturing Metal and Simulation of Laser Ultrasonic Test

电弧增材制造金属内部晶粒组织不均、呈叠层分布。为探究该特性对超声波传播的影响,制备了多层多道电弧增材金属试样,采用金相分析获得试样各区域的晶粒尺寸和分布。提出了一种以晶粒尺寸和晶粒取向分布为特征的叠层多晶结构整体建模方法,建立了电弧增材金属激光超声有限元仿真模型,并开展了激光超声检测实验,获得了实际激光超声纵波信号,仿真结果与实验结果基本吻合。该研究为叠层各向异性多晶材料建模以及揭示电弧增材制造材料中超声传播规律提供了理论和方法指导。

The grains in arc additive manufacturing metal are uneven and distributed in laminated form.In order to explore the influence of the characteristics on the ultrasonic propagation,the multi-layer muti-pass arc additive manufacturing metal sample was prepared,and the grain size and distribution of the sample in each region were obtained by using metallographic analysis.Overall modeling method for laminated polycrystalline structure was proposed based on the grain size and grain orientation distribution,and the finite element simulation model of laser ultrasound in arc increasing material was established.The laser ultrasonic testing experiment was carried out,and the actual laser ultrasonic longitudinal wave signal was obtained.The simulation results were consistent with the experimental results.This study provides theory and method guidance for modeling laminated anisotropic polycrystalline materials and revealing the law of ultrasonic propagation in arc additive manufacturing materials.