China Mechanical Engineering ›› 2021, Vol. 32 ›› Issue (17): 2108-2117,2124.

### Influences of Pulse Frequency on Microstructure and Properties in Laser Cladding Layers

LI Yunfeng1，2;SHI Yan1，2

1. 1.School of Electromechanical Engineering，Changchun University of Science and Technology，Changchun，130022
2.National Base of International Science and Technology Cooperation for Optics，Changchun，130022
• Online:2021-09-10 Published:2021-09-28

### 脉冲频率对激光熔覆层微观组织与性能的影响

1. 1.长春理工大学机电工程学院，长春，130022
2.科技部光学国际科技合作基地，长春，130022
• 通讯作者: 石岩（通信作者），男，1972年生，教授、博士研究生导师。研究方向为激光加工技术。发表论文40余篇，授权专利20余项。E-mail：shiyan@cust.edu.cn。
• 作者简介:李云峰，男，1989年生，博士研究生。研究方向为激光熔覆技术。发表论文9篇，授权专利8项。E-mail：gyhu22@163.com。
• 基金资助:
国家重点研发计划（2017YFB1104601）

Abstract:  The coarse grains and hard precipitates in the laser cladding layers had adverse effects on the corrosion resistance and impact resistance. The effects of pulse frequency on microstructure and properties of the coating were studied by pulse laser cladding technology. The microstructure of the coating was characterized by scanning electron microscope (SEM)morphology. High speed camera and numerical simulation method were used to analyze the shapes and temperature changes of molten pools. The hardness， wear resistance， impact resistance and corrosion resistance of the coating were tested by microhardness tester， wear tester， charpy impact tester and electrochemical corrosion tester respectively. The results show that the microstructure of the coating coarsens with the increase of pulse frequency. At the same time， the numbers of precipitates in the coating decrease first and then increase. The wear resistance of the coating decreases with the increase of pulse frequency. The wear resistance of the coating is the best because the microstructure of the coating is refined and there are fine hard precipitates at 20 Hz. The impact resistance and corrosion resistance of the coating increase first and then decrease with the increase of pulse frequency. Because the amount of hard phase in the coating decreases obviously at 80 Hz， the coating has the best impact resistance and corrosion resistance.

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