| 摘要: |
| 采用高功率半导体激光器在低碳钢表面激光熔覆了FeCoBSiNb合金涂层。借助光学显微镜、X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及数显维氏硬度计，探讨了激光功率对涂层稀释率、物相组成、微观组织及其显微硬度的影响。试验结果表明：在其它工艺参数一定的情况下，激光功率越大，涂层稀释率越大；激光功率为1 050 W时，涂层中部的物相分析表现为具有非晶特征的漫散射峰，微观组织由颗粒状晶体和无组织形貌特征的灰色基底组成，随着激光功率的增大，涂层中部的晶化相衍射峰逐渐增多增强，微观组织中出现“雪花”状晶体；涂层和基材结合区的微观组织以具有外延生长特征的平面晶和柱状树枝晶为主；涂层的平均硬度随激光功率的增大而降低。 |
| 关键词: 激光熔覆 非晶涂层 显微硬度 稀释率 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金(50971091)；科技部国际科技合作基金(2009DFB50350) |
|
| Effect of Laser Power on Microstructure and Properties of Laser Cladding FeCoBSiNb Coatings |
|
DAZE Xiao-li, ZHU Yan-yan, LI Zhu-guo
|
|
Shanghai Key Laboratory of Materials Laser Processing and Modification, Shanghai Jiao Tong University, Shanghai 200240
|
| Abstract: |
| The FeCoBSiNb alloy coatings were cladded on the mild carbon steel surface by a high power diode laser. The phase aggregate and microstructure were analyzed by Xray diffraction(XRD) and scanning electron microscope(SEM), respectively. The size of coatings was measured by optical microscope, and microhardness was assessed using Vickers microhardness tester. The effect of laser power on coatings was studied. The results show that the coating dilution increases with increasing laser power when the other parameters are fixed. When the laser power was 1 050 W, an amorphous phase occurred in the coating. Granular crystals and a large grey area were observed in the middle of the coating. With increasing laser power, crystalline phases in the coating gradually increased and snowlike crystals were formed in the middle of the coating. The microstructures on the coatingsubstrate interface were plane crystal and columnardendrite crystals, which exhibited obvious extensive growth characteristics. The hardness of the coating decreased with increasing laser power. |
| Key words: laser cladding amorphous microhardness dilution rate |
