激光功率对Fe-Si-B激光熔覆涂层微观组织与性能的影响

Effect of laser power on microstructure and property of Fe-Si-B laser cladded layers

选取工业化生产的Fe-Si-B粉末为原料,采用激光熔化沉积技术分别在800、1000和1200 W的激光功率下在45钢基体表面制备了致密的Fe-Si-B熔覆层。采用X射线衍射分析仪、差示扫描量热仪、光学显微镜、扫描电镜、显微硬度仪研究了激光功率对熔覆层微观组织与性能的影响。结果表明：制备的Fe-Si-B熔覆层均由（Fe,Si）树枝晶以及Fe2B与（Fe,Si）的片状共晶组织构成,其中（Fe,Si）树枝晶数量与尺寸均随熔覆功率的增加而增加;熔覆层硬度随熔覆功率的下降而提高,最高可达（726±10）HV0.5,为基体的3.7倍,取得了良好的表面强化效果。

The dense Fe-Si-B cladding layers were prepared on the surface of 45 steel substrate by laser cladding deposition technique at the laser power of 800,1000 and 1200 W,respectively,using industrialized Fe-Si-B powder as raw materials. The effect of laser power on microstructure and properties of the cladding layers was studied by means of X-ray diffraction（ XRD）,differential scanning calorimeter（ DSC）,optical microscope（ OM）,scanning electron microscopy（ SEM） and microhardness tester. The results show that the Fe-Si-B layers are composed of（ Fe,Si） dendrites and lamellar eutectic structure of Fe2 B and（ Fe,Si）. in which the number and size of（ Fe,Si） dendrites increase with the increasing of laser power,and the hardness of the cladding layers increases with the decreasing of laser power,the maximum value is（ 726 ± 10） HV0. 5,which is 3. 7 times of that of the substrate,and a good surface strengthening effect is obtained.