姚喆赫,沈奇艳,葛宏江,王振,董刚,叶钟,李琳,姚建华.超声对激光熔覆成形中熔池润湿行为的影响研究[J].表面技术,2022,51(10):20-29.
YAO Zhe-he,SHEN Qi-yan,GE Hong-jiang,WANG Zhen,DONG Gang,YE Zhong,LI Lin,YAO Jian-hua.Influence of Ultrasound on the Wetting Behavior of Molten Pool in Laser Cladding[J].Surface Technology,2022,51(10):20-29 |
| 超声对激光熔覆成形中熔池润湿行为的影响研究 |
| Influence of Ultrasound on the Wetting Behavior of Molten Pool in Laser Cladding |
| |
| DOI：10.16490/j.cnki.issn.1001-3660.2022.10.003 |
| 中文关键词: 激光熔覆 超声振动 润湿行为 熔池 宏观形貌 微观组织 |
| 英文关键词:laser cladding ultrasonic vibration wetting behavior molten pool macroscopic morphology microstructure |
| 基金项目:国家自然科学基金（52175443、U1809220）；浙江省属高校基本科研业务费专项资金（RF-B2020002）；浙江省公益技术应用研究项目（LGG20E050019） |
|
|
| Author | Institution |
| YAO Zhe-he | Institute of Laser Advanced Manufacturing,Hangzhou 310023, China ;College of Mechanical Engineering, Zhejiang University of Technology,Hangzhou 310023, China ;Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310023, China |
| SHEN Qi-yan | Institute of Laser Advanced Manufacturing,Hangzhou 310023, China ;College of Mechanical Engineering, Zhejiang University of Technology,Hangzhou 310023, China ;Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310023, China |
| GE Hong-jiang | Hangzhou Steam Turbine Co., Ltd., Hangzhou 310020, China |
| WANG Zhen | Institute of Laser Advanced Manufacturing,Hangzhou 310023, China ;College of Mechanical Engineering, Zhejiang University of Technology,Hangzhou 310023, China ;Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310023, China |
| DONG Gang | Institute of Laser Advanced Manufacturing,Hangzhou 310023, China ;College of Mechanical Engineering, Zhejiang University of Technology,Hangzhou 310023, China ;Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310023, China |
| YE Zhong | Hangzhou Steam Turbine Co., Ltd., Hangzhou 310020, China |
| LI Lin | Laser Processing Research Centre, University of Manchester, Manchester M13 9PL, UK |
| YAO Jian-hua | Institute of Laser Advanced Manufacturing,Hangzhou 310023, China ;College of Mechanical Engineering, Zhejiang University of Technology,Hangzhou 310023, China ;Collaborative Innovation Center of High-end Laser Manufacturing Equipment, Hangzhou 310023, China |
|
| 摘要点击次数: |
| 全文下载次数: |
| 中文摘要: |
| 目的 对比有无超声作用下熔体润湿行为，阐明超声对于熔体润湿行为的影响及作用机制，为超声辅助激光熔覆高质量成形提供参考。方法 基于高速相机拍摄研究了超声对于液滴润湿性的作用效果，进而研究了超声辅助激光熔覆过程中熔池的润湿行为，使用Canny算法提取熔池轮廓，采用体视显微镜和共聚焦显微镜观察试样宏观形貌，采用光学显微镜观察分析微观组织。结果 将超声振动施加于金属液滴，其在基板表面润湿性增强，金属液滴与基板接触面积增大39.3%。在熔覆过程中引入超声振动，熔池面积显著增大。随着超声功率比的增强，熔覆层的熔高降低，熔深减小，熔宽逐渐增大，熔覆层逐渐由弧形轮廓变为扁平。当超声功率比为80%时，熔覆层高度为无超声下的75.2%，熔覆层和基体之间的润湿性显著改善。在微观形貌上，超声能够改变晶粒生长方向，抑制枝晶外延生长。结论 超声振动作用于激光熔覆过程中，促进了熔体的润湿作用且加大了熔池流动性。熔体润湿行为的改变导致扁平熔覆层形状的形成，熔覆过程中熔池面积增大，熔池流动性增强，导致晶粒生长方向与枝晶长度的改变。 |
| 英文摘要: |
| Laser additive remanufacturing technology based on laser cladding has shown significant advantages and great potential in the repair and remanufacturing of damaged parts. However, the rapid heating and cooling process during laser cladding leads to the formation of micro-cracks, pores, residual tensile stress, etc. in the cladding layer. In order to improve the quality of laser cladding, ultrasonic assisted laser cladding has become one of the hot spots in current research. In this study, the wetting behaviors of the molten pool with and without ultrasonic vibration were compared to investigate the influence and mechanism of ultrasonic vibration on the wetting behavior, providing reference for high-quality ultrasonic assisted laser cladding.Inconel 718 substrates were polished and cleaned by alcohol to remove surface impurities. A laser beam with power of 1 kW and a spot diameter of 2 mm was used. Ultrasonic vibration with a frequency of 20 kHz and amplitude of 50 μm was transmitted from the bottom of the specimen to the molten pool. A forward wire feeding with a feeding angle of 45° was applied. The scanning speed and the wire feeding speed were 8 mm/s and 9.3 mm/s, respectively. During the experiments, the transition behaviors of the molten pool were captured by a high-speed camera, and the profiles of the molten pool were extracted by Canny algorithm. After the experiments, the macro morphology of the specimens was observed using a stereo microscope (Nikon, SMZ745T) and a confocal microscope (Keyence, VK-X1000). An optical microscope (Zeiss, Axio Imager2) was used to observe and analyze the microstructure of the cladding zone.Significant fluctuation occurred on the surface of metal droplet with ultrasonic vibration. And the contact area between the metal droplet and the substrate increased by 39.3% with the effect of ultrasonic vibration, indicating the increase of wettability. The area of the molten pool in the laser cladding increased significantly caused by ultrasonic vibration. When a stable liquid-bridge transition was reached in the laser cladding, the area of the molten pool with ultrasonic vibration was 2.8 times of that without ultrasonic vibration. With the increase of ultrasonic power, the height and depth of the cladding layer decreased while the width increased. The dilution rate of the cladding layer was also reduced by ultrasonic vibration. And the cladding layer gradually varied from an arc profile to be relatively flat. When the ultrasonic power ratio was 80%, the height of the cladding layer was 75.2% of that without ultrasound, suggesting significant improvement of the wettability between the cladding and the substrate. In addition, the growth direction of the grains changed and the epitaxial growth of dendrites was inhibited. In addition, the turning dendritic structure at the top of the cladding layer became narrow with ultrasonic vibration. The mechanisms of ultrasonic vibration on the molten pool were discussed based on the experimental results. In the laser cladding process, ultrasonic vibration is able to promote the wetting of melt and accelerate the melt flow of the molten pool, which leads to a relatively flat cladding layer. The area of molten pool increased, resulting in the variation of the grain growth direction and the length of dendrites. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
渝公网安备 50010702501715号