Abrasive wear behaviour of laser clad and flame sprayed-melted NiCrBSi coatings
Abrasive wear behaviour of laser clad and flame sprayed-melted NiCrBSi coatings
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DOI：
10.1016/j.surfcoat.2005.10.032
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发表时间：
2006-08
影响因子：
5.4
通讯作者：
C. Navas;R. Colaço;J. Damborenea;R. Vilar
中科院分区：
文献类型：
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作者：
C. Navas;R. Colaço;J. Damborenea;R. Vilar
分析了工艺条件对NiCrBSi堆焊合金组织和磨料磨损性能的影响。采用激光熔覆(LC)和火焰喷涂(FS)结合表面火焰熔化(SFM)等不同工艺，在低碳钢(Fe-0.15%C)表面以涂层的形式进行堆焊。在这两种情况下，工艺参数的适当选择都能够获得高质量、无缺陷的NiCrBSi涂层。用扫描电子显微镜(SEM)、电子能谱(EDS)和X射线衍射仪(X射线衍射仪)分析了涂层的微观结构。以金刚石、碳化硅和碳化钨为磨料，通过微球磨粒磨损试验评价了它们的摩擦学性能。显微组织分析表明，两种涂层的显微组织结构相似，但不同涂层的相形态、尺寸分布和相对比例不同。磨损试验表明，在三体磨损条件下，尽管组织结构不同，两种涂层的磨损行为是相似的。相反，在以金刚石颗粒为磨料的两体磨损条件下，观察到材料的比磨损率对组织变化敏感。这一事实在LC涂层中尤其明显，在LC涂层中，具有非常小的硬颗粒比例较高的层的区域表现出较低的耐磨性。这些结果表明，为了获得摩擦学性能最佳且均匀的涂层，对该材料进行良好的组织控制是很重要的。
In this work, the influence of the processing conditions on the microstructure and abrasive wear behaviour of a NiCrBSi hardfacing alloy is analysed. The hardfacing alloy was applied in the form of coatings onto a mild steel substrate (Fe–0.15%C) by different techniques: laser cladding (LC) and flame spraying (FS) combined with surface flame melting (SFM). In both cases, the appropriate selection of the process parameters enabled high-quality, defect-free NiCrBSi coatings to be obtained. The microstructure of the coatings was analysed by scanning electron microscopy (SEM), with attached energy dispersive spectroscopy (EDS) microprobe, and by X-ray diffraction (XRD). Their tribological properties were evaluated by micro-scale ball cratering abrasive wear tests using different abrasives: diamond, SiC and WC. Microstructural characterisation showed that both coatings exhibit similar phases in their microstructure, but the phases present differ in morphology, size distribution and relative proportions from one coating to another. Wear tests showed that in three-body abrasive conditions, despite these microstructural differences, the wear behaviour is comparable for both coatings. Conversely, in two-body wear conditions with diamond particles as the abrasive, it was observed that the specific wear rate of the material is sensitive to microstructural changes. This fact is particularly apparent in LC coatings, in which the zones of the layers with higher proportions of very small hard particles present a lower wear resistance. These results indicate that it is important to have good microstructural control of this material, in order to obtain coatings with an optimized and homogeneous tribological behaviour.