工艺参数对LDED成形热作模具钢熔池形貌及成形质量的影响OA
Effect of Processing Parameters on the Molten Pool Morphology and Forming Quality of a Hot Work Tool Steel Fabricated via Laser Directed Energy Deposition
激光定向能量沉积技术可实现热作模具钢复杂构件的近净成形与高效修复,在模锻、压铸等高温服役模具的制造与再制造中具有明显应用优势,但成形过程中工艺参数波动易影响熔池形貌特征,同时工艺参数的不合理匹配也易引发孔隙、裂纹等成形缺陷,从而制约成形质量稳定性.为明确工艺参数在激光定向能量沉积成形热作模具钢过程中的影响机制,本研究围绕工艺参数-熔池形貌-成形质量之间的关联关系,依次开展单层单道、单层多道及多层多道沉积试验,系统研究了主要工艺参数对熔池形貌演化行为及沉积件成形质量的调控规律.结果表明,激光功率和扫描速度主导熔池熔化深度与宽度,送粉量与前两者协同决定熔池填充状态;搭接率处于30%～50%区间时可以有效避免道间沟槽、单侧堆积及界面缝隙等缺陷;在激光比能量与绝对送粉率适配形成的最优成形工艺窗口内,可保障粉末完全熔融、层间冶金结合良好且气体充分逸出,使成形件致密度达99%以上且无明显缺陷,参数偏离则会导致因能量与粉末输入失衡引发的未熔合、裂纹或匙孔等缺陷,进而劣化成形质量.该研究结果明确了工艺参数对熔池形貌的调控机制,为激光定向能量沉积成形热作模具钢的工艺参数优化及成形质量控制提供了试验依据.
Laser directed energy deposition enables near-net-shape fabrication and efficient repair of complex hot work tool steel components,offering clear advantages for the manufacturing and remanufacturing of dies used under high-temperature service conditions such as hot forging and die casting.However,during the forming process,fluctuations in process parameters tend to affect the morphological characteristics of the molten pool,while unreasonable matching of process parameters can easily induce forming defects such as pores and cracks,thereby restricting the stability of forming quality.To clarify the influence mechanisms of processing parameters in the laser directed energy deposition forming of hot work tool steel,and focusing on the correlations among processing parameters,molten pool morphology,and forming quality,the single-layer single-track,single-layer multi-track,and multi-layer multi-track deposition experiments were carried out sequentially to systematically investigate the regulatory effects of key processing parameters on the evolution of molten pool morphology and the forming quality of deposited parts in this study.The results indicate that laser power and scanning speed dominate the melting depth and width of the molten pool,while the powder feeding rate acts synergistically with them to determine the molten pool filling state;when the overlap ratio is in the range of 30%-50%,the defects such as inter-track grooves,unilateral accumulation,and interfacial gaps can be effectively avoided;within the optimal forming process window established by the appropriate matching of laser specific energy and absolute powder feeding rate,complete powder melting,sound interlayer metallurgical bonding,and sufficient gas escape can be ensured,resulting in a relative density exceeding 99%without obvious defects.In contrast,deviations from this parameter window lead to defects such as lack of fusion,cracks,or keyholes caused by an imbalance between energy input and powder supply,thereby deteriorating the forming quality.These results clarify the regulation mechanism of processing parameters on molten pool morphology and provide experimental basis for process parameter optimization and forming quality control in the laser directed energy deposition fabrication of hot work tool steel.
郑若璇;侯英培;万杰;王媛媛;王一男;杨海欧;林鑫;陈豫增
西北工业大学 凝固技术全国重点实验室,陕西 西安 710072西北工业大学 凝固技术全国重点实验室,陕西 西安 710072西北工业大学 凝固技术全国重点实验室,陕西 西安 710072苏州匀晶金属科技有限公司,江苏 苏州 215024一汽铸造有限公司,吉林 长春 130011西北工业大学 凝固技术全国重点实验室,陕西 西安 710072西北工业大学 凝固技术全国重点实验室,陕西 西安 710072西北工业大学 凝固技术全国重点实验室,陕西 西安 710072||苏州匀晶金属科技有限公司,江苏 苏州 215024||西北工业大学宁波研究院,浙江 宁波 315103
矿业与冶金
激光定向能量沉积热作模具钢工艺参数熔池形貌成形质量冶金结合工艺窗口缺陷控制
laser directed energy depositionhot work tool steelprocess parametermolten pool morphologyforming qualitymetallurgical bondingprocess windowdefect control
《铸造》 2026 (6)
568-580,13
国家重点研发计划项目课题(2024YFB3713303)国家自然科学基金项目(52531002、52571052)凝固技术全国重点实验室(西北工业大学)自主研究课题(2024-ZD-06).
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