高频感应重熔处理火焰喷涂NiCrBSi涂层的显微组织与力学性能  

Microstructure and Mechanical Properties of Flame Spray NiCrBSi Coating Remelted by High Frequency Induction Heating

作　　者：赵锐[1,2] 杨红军[3] 于鹤龙[1] 张梦清 周克兵[1] 张伟[1] 

机构地区：[1]装甲兵工程学院再制造技术重点实验室 [2]中国人民解放军66222部队 [3]中国人民解放军76327部队

出　　处：《中国表面工程》2016年第3期65-73,共9页China Surface Engineering

基　　金：北京市自然科学基金(3132024)

摘　　要：采用高频感应加热技术对普通火焰喷涂NiCrBSi涂层进行了重熔处理,分析了重熔后涂层的显微组织与力学性能,探讨了涂层显微组织、单一析出相微/纳力学性能之间的对应关系。结果表明,重熔后NiCrBSi涂层的层状结构与孔隙消失,涂层/基体界面形成了代表涂层冶金结合特征、厚度约为10μm的"白区"显微组织,涂层成分在原有γ-Ni、Ni_3Fe和M_(23)C_6型碳化物基础上,出现了Fe_3C、Ni_3B、以及Cr_7C_3和CrB析出相;重熔后涂层显微硬度沿表面至基体方向呈近似线性逐渐降低,表层显微硬度约为675 HV_(0.2),接近界面区域硬度降至440 HV_(0.2),涂层内部Cr_7C_3、CrB、γ-Ni和"白区"纳米压痕硬度分别为19.2、7.0、5.0和4.2 GPa;涂层硬度变化符合"复合材料混合定律",由各物相分布及其硬度共同决定。Remelting treatment of flame-sprayed NiCrBSi coating was conducted by high frequency induction heating technique to improve the quality of the coating. The correlation between the remelted coating microstructure and micro/nano scale mechanical properties was discussed based on the microstructure observation, nanoindentation and microhardness measurement. Results show that the induction remelted NiCrBSi coating exhibits a pore-free microstructure. A white zone, with a thickness of 10 μm, is observed on the interface, which is the characteristic of a good metallurgical bond between the coating and the substrate. Besides, the original phases of γ-Ni, Ni3Fe and M23C6 in the as sprayed coating, Fe3C, Ni3B and precipitated phases of M7C3 and CrB appear in the remelted coating. The microhardness of the remelted coating is reduced from 675 HV0.2 at the position near surface to about 440 HVo.2 at the position near interface. The nanoindentation hardness of the phase of Cr7C3, CrB and γ-Ni, and the white zone are 19.2, 7.0, 5.0 and 4.2 GPa, respectively. The hardness evolution obeys the Rule of Mixtures： determined by the fraction and the hardness of the phases in the remelted coating.

关 键 词：感应加热 重熔处理 NiCrBSi涂层 显微组织 纳米压痕 

分 类 号：TG174.44[金属学及工艺—金属表面处理]