工程科学与技术2025，Vol.57Issue(3)：267-277,11.DOI:10.12454/j.jsuese.202300627
能量密度对于选区激光熔化成型Ti6Al4V合金缺陷特征的影响
Effect of Energy Density on Defect Characteristics of Ti6Al4V Alloy Formed by Selective Laser Melting
摘要
Abstract
This study investigates the formation mechanisms and suppression strategies for common metallurgical defects—including balling,po-rosity,powder adhesion,and spatter—in Ti6Al4V alloys fabricated by selective laser melting(SLM).A comprehensive numerical framework link-ing process parameters,molten pool dynamics,and defect evolution is developed to optimize linear and volumetric energy densities.This re-search further proposes actionable guidelines aimed at achieving high-quality manufacturing outcomes in SLM processes.A three-dimensional transient thermal-fluid flow model for SLM-processed Ti6Al4V powder was established to elucidate molten pool dynamics under controlled pro-cessing conditions.Utilizing dimensionless numbers to quantify dynamic behaviors,the simulations were optimized to accurately capture molten pool evolution.Defect formation mechanisms,particularly for balling and porosity,were thoroughly examined through integrated numerical mod-eling and experimental validation,emphasizing the critical impact of linear and volumetric energy densities.The analysis revealed that thermal convection predominantly governs heat transfer within the molten pool,driven primarily by evaporation recoil pressure,surface tension,and Ma-rangoni shear stress.A reduction in energy density adversely affects molten pool fluidity,promoting porosity formation as molten metal solidifies into spherical shapes driven by surface tension.This resultant porosity significantly deteriorates the mechanical properties of fabricated parts,un-derscoring the necessity for meticulous control over energy density.Optimizing key processing parameters,such as laser power,scanning speed,and scanning spacing,enables the formation of high-quality components.The proposed"process parameters-molten pool characteristics-forming quality"analytical framework provides robust guidance for parameter optimization.Application of this framework effectively mitigates metallur-gical defects,thereby enhancing the density and mechanical performance of parts manufactured through SLM.关键词
选区激光熔化/熔池/Ti6Al4V/加工缺陷/工艺参数Key words
selective laser melting/molten pool/Ti6Al4V/processing defects/process parameters分类
金属材料引用本文复制引用
陈东菊,高超,范晋伟,潘日,孙锟,郑宸..能量密度对于选区激光熔化成型Ti6Al4V合金缺陷特征的影响[J].工程科学与技术,2025,57(3):267-277,11.基金项目
国家自然科学基金项目(52475423) （52475423）
