Ni-W(D)/CeO_2纳米复合刷镀层耐高温性能研究

Research on High Temperature Oxidation Resistance of Ni-W(D)/CeO_2 Nanoparticle Composite Coating Prepared by Electro-brush Plating

利用电刷镀技术制备了Ni-W(D)/CeO_2复合镀层。采用扫描电镜、显微硬度计等对镀层组织和耐高温性能进行了测定分析。结果表明,与Ni-W(D)合金镀层相比,Ni-W(D)/CeO_2复合镀层表面组织更加平整致密,裂纹减少且宽度减小;热处理后依然维持较高的显微硬度。高温氧化后增重明显低于Ni-W(D)合金镀层,表面依然保持平整。由于CeO_2纳米颗粒在镀层中的均匀分布有细化晶粒、减小裂纹宽度的作用,降低了O、Ni沿裂纹和晶界的扩散速率,提高了镀层的耐高温氧化性能。

Ni-W（D）/CeO2 nanoparticle composite coating was prepared by electro-brush plating. Microstructure and high temperature oxidation resistance of the coating were measured and analyzed by scan electronic microscope and microhardness tester etc. The results show that compared with Ni-W（D） coating, surface morphology of Ni-W（D）/CeO2 composite coating is relatively smooth and compact. Number of cracks and crack width reduce. The composite coating still keeps high micro- hardness after heat treatment. After high temperature oxidation, weight gain of the composite coating is significantly lower than that of Ni-W（D） alloy coating and surface of the composite coating still keeps smooth. Due to grain refinement and small crack width caused by dispersive distribution of CeO2 nanoparticles in the coating, the diffusion rate of O and Ni through crack and grain boundary decreases and high temperature oxidation resistance of the coating increases.