| 摘要: |
| 基于激光熔覆同轴送粉技术，在不锈钢基板表面制备了321不锈钢合金涂层，研究了工艺参数对涂层宏观形貌的影响，分析了涂层的显微组织和显微硬度。研究结果表明：在激光功率为2.2kW，扫描速度为7mm/s，送粉速率为13.2g/min，搭接率为30%时，可获得平整无缺陷的321不锈钢涂层。熔覆层可分为一次熔化区、道间重熔区和层间重熔区三部分。熔覆层的组织主要由胞状晶和树枝晶构成；相比于一次熔化区，道间重熔区和层间重熔区的组织较为粗大且硬度较低。在激光熔覆过程中，成形件产生了较为明显的变形，通过改变成形路径可以减小基板变形量，提升成形件的质量。 |
| 关键词: 增材制造 宏观形貌 微观组织 显微硬度 变形控制 |
| 基金项目: |
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| Study on Laser Additive Manufacturing Technology and Deformation of 321 Stainless Steel |
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Wang Zhaoyang1, Li Jinquan1, Xiao Changyuan1, Yuan Liming1, Lin Jian2, Lei Yongping2, Li Kangli2
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1. Capital Aerospace Machinery Co., Ltd., Beijing 100076;2. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100076
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| Abstract: |
| Based on the technology of laser cladding using coaxial powder feeding, the 321 stainless steel alloy coating was coated on the surface of stainless steel. The effects of processing parameters on the macroscopic morphology of the coating were studied, the microstructure and microhardness of the coating were analyzed. The results showed that the flat and defect-free 321 stainless steel coating could be obtained at the laser power, the scanning speed, the powder feeding rate and the lap ratio of 2.2kW, 7mm/s, 13.2g/min, and 30%, respectively. The structure section of the cladding layer included three zones, including primary melting zones, inter-channel remelting zones, and inter-layer remelting zones. The microstructures of the cladding layer were composed of cell and dendrites crystals. Compared with the primary melting zone, the microstructures of inter-channel remelting zone and the inter-layer remelting zone were coarse and accompanied with the decrease of the microhardness. In the process of laser cladding, the deformation of substrate is obvious. By changing the forming path, the deformation of the substrate can be reduced and the quality of the formed parts can be improved. |
| Key words: additive manufacturing macroscopic morphology microstructure microhardness deformation control |
