叶秀,武美萍,缪小进,陆佩佩.激光重熔对Ti-6Al-4V选区激光熔化成形质量的影响[J].表面技术,2021,50(8):301-310.
YE Xiu,WU Mei-ping,MIAO Xiao-jin,LU Pei-pei.Influence of Laser Remelting on Forming Quality of Ti-6Al-4V Fabricated by Selective Laser Melting[J].Surface Technology,2021,50(8):301-310 |
| 激光重熔对Ti-6Al-4V选区激光熔化成形质量的影响 |
| Influence of Laser Remelting on Forming Quality of Ti-6Al-4V Fabricated by Selective Laser Melting |
| 投稿时间：2020-07-03 修订日期：2020-11-19 |
| DOI：10.16490/j.cnki.issn.1001-3660.2021.08.028 |
| 中文关键词: 选区激光熔化 激光重熔 Ti-6Al-4V 致密度 耐磨损性能 |
| 英文关键词:selective laser melting laser remelting Ti-6Al-4V density wear resistance |
| 基金项目:装备预研教育部联合基金项目(6141A0221) |
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| Author | Institution |
| YE Xiu | School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China |
| WU Mei-ping | School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China |
| MIAO Xiao-jin | School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China |
| LU Pei-pei | School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China |
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| 中文摘要: |
| 目的 针对选区激光熔化(Selective Laser Melting, SLM)成形Ti-6Al-4V过程中易产生孔隙缺陷、成形质量差等问题，提出“初次扫描+低激光功率重熔”的成形方式，研究激光重熔对SLM成形质量的影响机制以及重熔功率对成形质量的影响规律，优化工艺参数。方法 基于ANSYS软件，模拟SLM加工过程及激光重熔过程的熔池、温度场分布，利用金相显微镜观测成形件截面缺陷形态、分布及金相显微组织，并利用显微硬度计及摩擦磨损试验机分别测试成形件的显微硬度及摩擦磨损性能。结果 随着激光重熔功率的增大，重熔熔池尺寸增大，温度梯度过渡渐缓，初次扫描形成的缺陷经重熔后得以填补，试件孔隙逐渐减小。当激光重熔功率为120 W时，成形件的致密度达到99.89%;当激光重熔功率为100 W时，成形件的硬度达到444.0HV0.3，相较于未重熔件提高了21.0%，平均摩擦系数为0.396，相较于未重熔件降低了13.73%。结论 激光重熔可以有效提高SLM成形件的致密度、显微硬度及摩擦磨损性能。随着激光重熔功率的增大，成形件的熔池范围扩大，初次成形的孔隙尺寸明显减小，成形件中的β相晶界扩展，针状马氏体尺寸增大，显微硬度得以提升。当激光重熔功率为140 W时，熔池剧烈波动，凝固过程中较大的固态收缩使成形质量出现下降趋势。 |
| 英文摘要: |
| In view of the problems such as porosity defects and poor forming quality of Ti-6Al-4V alloy formed by (Selective laser melting, SLM), the processing method of “initial scanning+low laser power remelting” is proposed to study the influence mechanism of laser remelting on the forming quality and the effect of remelting power on forming quality to optimize the parameters. In this paper, the molten pool and temperature field distribution of SLM processing and laser remelting process are studied based on ANSYS software. The morphology, distribution of the defects and the microstructure of cross-section are observed by metallographic microscope. The microhardness and friction and wear properties are tested by microhardness tester and friction and wear tester, respectively. The results indicate that with the increase of laser remelting power, the size of remelting pool increased, and the temperature gradient transition gradually slowed down. The defects formed in the initial scanning could be filled after remelting, and the porosity of the specimens decreased gradually. When the laser remelting power was 120 W, the density of the formed part reached 99.89%; When the laser remelting power was 100 W, the hardness of the formed parts reached 444.0HV0.3, which was 21.0% higher than that of the sample not remelted, and the average friction coefficient was 0.396, which was 13.73% lower than that of the sample not remelted. We can conclude that laser remelting can effectively improve the density, microhardness and friction and wear properties of SLM parts. With the increase of laser remelting power, the range of molten pool is enlarged, and the size of pores formed in the process of first scanning decreases obviously. The grain boundary of β phase expands, the size of acicular martensite increases, and the microhardness is improved. When the remelting power is 140 W, the effect of molten pool is intense and the solid shrinkage in solidification process makes the forming quality decrease. |
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