摘要
本文基于ANSYS软件建立了选区激光熔化(SLM)成形Fe_(81)Ga_(19)合金的有限元模型,采用APDL命令流结合生死单元技术实现了高斯热源的动态移动.通过数值模拟与实验相结合的方法,系统研究了激光功率、扫描速度、扫描间距及预热温度等工艺参数对熔池形貌、温度场分布及力学性能的影响规律.研究结果表明,熔池的最高温度及尺寸随激光功率增大而显著增加,随扫描速度增大而减小;熔池冷却速率则随激光功率和扫描速度的增大而同步提升.扫描间距的增大会导致预热与后热区的峰值温度下降,而预热温度的降低则会加速节点的温度变化速率.在优化工艺参数(激光功率105 W、扫描速度1200 mm·s^(−1)、扫描间距60μm、粉层厚度30μm、67°旋转扫描)下,熔池宽度为65.5μm,深度为37.4μm,宽深比为1.75,成形试样的致密度达到98.63%,显微硬度和压缩屈服强度分别提升至310.9 HV和701.1 MPa,综合力学性能最佳.本研究为Fe–Ga合金SLM成形工艺的优化提供了理论依据与实验支持.
Fe–Ga(Galfenol)alloys have attracted significant attention as next-generation magnetostrictive materials due to their unique combination of large low-field magnetostriction(~4×10^(−4)),excellent mechanical durability,and corrosion resistance.Unlike rare-earth-based magnetostrictive materials,these iron-gallium alloys offer substantial cost advantages and environmental benefits,making them particularly suitable for precision actuators,vibration energy harvesters,and underwater transducers.However,conventional manufacturing methods for Fe–Ga alloys face challenges in achieving complex geometries while maintaining the desired magnetostrictive performance.Selective laser melting(SLM),a prominent powder bed fusion(PBF)technology,offers distinct advantages including rapid processing cycles,high design flexibility,the ability to fabricate complex geometries,and superior component performance.In SLM processing,energy-related processing parameters such as laser power,scanning speed,and beam spot size-which govern the point-wise powder melting behavior-critically determine the resultant microstructure and part quality.Additionally,discontinuous parameters,including scan spacing,layer thickness,and scanning strategy,are geometrically related to scan path and build layers.These factors primarily determine the spatial overlap between adjacent melt tracks,in which scanning strategy plays a crucial role by modifying melt pool dynamics and thermal gradients,thereby affecting grain structure and mechanical properties.To achieve defect-free Fe-Ga alloys with superior performance through PBF,precise control of both energy-related and geometric parameters is essential.This study presents a comprehensive investigation into the SLM process of Fe_(81)Ga_(19) alloy,combining finite element simulation and experimental validation to optimize process parameters and enhance mechanical properties.A high-fidelity 3D finite element model was developed using ANSYS software,incorporating temperature-dependent material properties,latent heat effects,and nonlinear thermal boundary conditions.The dynamic laser scanning process was accurately simulated using APDL programming with the birth-and-death element technique,enabling precise modeling of the moving Gaussian heat source and layer-by-layer deposition.The research systematically examines the influence of critical process parameters-laser power(95-110 W),scanning speed(800-1400 mm·s^(−1)),hatch spacing(50-65μm),and preheating temperature(25-200°C)-on melt pool characteristics,thermal behavior,and mechanical performance.The key findings reveal that(1)the melt pool peak temperature increases as laser power rises from 95 W to 110 W,while doubling the scanning speed reduces the melt pool length due to decreased energy input;(2)the cooling rate exhibits a strong positive correlation with both laser power and scanning speed;and(3)a novel 67°interlayer rotation scanning strategy effectively reduces thermal anisotropy,minimizing residual stresses compared to unidirectional scanning.Through multi-objective optimization,the study identifies that under optimized process parameters(laser power:105 W,scanning speed:1200 mm·s^(−1),hatch spacing:60μm,layer thickness:30μm,and 67°rotation scanning),the melt pool width and depth reached 65.5μm and 37.4μm,respectively,with a width-to-depth ratio of 1.75.The as-built sample exhibited a density of 98.63%,while the microhardness and compressive yield strength improved to 310.9 HV and 701.1 MPa,respectively,demonstrating optimal comprehensive mechanical properties.This research establishes quantitative process-property relationships and provides a validated numerical framework for SLM parameter optimization of magnetostrictive alloys,offering significant guidance for the industrial applications of Fe-Ga components in smart actuators and sensors.
作者
麻志勇
张文格
马好放
杨小康
王泽
刘龙龙
杨丹
胡勇
MA Zhiyong;ZHANG Wenge;MA Haofang;YANG Xiaokang;WANG Ze;LIU Longlong;YANG Dan;HU Yong(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Wenzhou Pump and Valve Engineering Research Institute,Lanzhou University of Technology,Wenzhou 325000,China)
出处
《工程科学学报》
北大核心
2026年第4期766-779,共14页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(12264024,52565039)
甘肃省重点研发计划—工业类资助项目(22YF7GA156)
甘肃省科技重大专项计划资助项目(23ZDGA01,22ZD6GA008)
兰州理工大学红柳一流学科建设基金资助项目(CGZH001)。
关键词
铁镓合金
选区激光熔化
温度场
工艺参数
数值模拟
iron-gallium alloy
selective laser melting
temperaturefield
process parameters
numerical simulation
