Comparison of the Microstructure Evolution and Wear Resistance of Ti6Al4V Composite Coatings Reinforced by Hard Pure or Ni-plated Cubic Boron Nitride Particles Prepared with Laser Cladding on a Ti6Al4V Substrate
Comparison of the Microstructure Evolution and Wear Resistance of Ti6Al4V Composite Coatings Reinforced by Hard Pure or Ni-plated Cubic Boron Nitride Particles Prepared with Laser Cladding on a Ti6Al4V Substrate
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DOI：
10.3390/coatings10070702
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发表时间：
2020-07
期刊：
影响因子：
3.4
通讯作者：
Shuren Fu;Yang Lijing;Wang Pei;Shao-peng Wang;Zheng-Xian Li
中科院分区：
文献类型：
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作者：
Shuren Fu;Yang Lijing;Wang Pei;Shao-peng Wang;Zheng-Xian Li
钛合金是航空航天领域的主要结构材料，具有优异的高比强度。立方氮化硼（cBN）是一种合成的耐磨材料，具有高硬度，类似于金刚石，用于机械切割和磨削。此外，立方氮化硼颗粒的热稳定性比金刚石好得多。为了进一步提高Ti6 Al 4V合金的耐磨性，利用激光熔覆（LC）技术的冶金结合特性，在Ti6 Al 4V基体上制备了立方氮化硼/Ti6 Al 4V和镀Ni立方氮化硼/Ti6 Al 4V复合涂层。然而，在激光熔池中，很难在激光辐射下保持立方氮化硼颗粒的原始性能。采用扫描电子显微镜（SEM）、能谱仪（EDS）、X射线衍射仪（XRD）和X射线光电子能谱仪（XPS）对两种复合涂层进行了分析。利用扫描电子显微镜（SEM）观察了立方氮化硼颗粒与Ti6 Al 4V基体之间的显微组织和界面结合情况，并利用球盘式磨损试验机和台阶轮廓仪（WTM-2 E）评价了复合涂层的耐磨性和磨痕形态。结果表明，与立方氮化硼/Ti6 Al 4V复合涂层相比，镀镍立方氮化硼/Ti6 Al 4V复合涂层具有更少的热缺陷。通过在立方氮化硼颗粒表面镀Ni，可以避免复合镀层中立方氮化硼颗粒热裂纹的产生。在立方氮化硼颗粒与Ti6 Al 4V基体之间形成了TiN反应层，有效地阻止了立方氮化硼颗粒的进一步分解。XRD和XPS分析结果证实了立方氮化硼颗粒与Ti6 Al 4V之间形成了TiN反应层。立方氮化硼颗粒表面镀Ni也有利于提高复合镀层的耐磨性。
Titanium alloy is a major structural material with excellent high specific strength in aerospace applications. Cubic boron nitride (cBN) is a synthetic wear-resistant material with high hardness, similar to that of diamond, that is used in mechanical cutting and grinding. In addition, the thermal stability of cubic boron nitride particles is much better than that of diamond. In order to further enhance the wear resistance of the Ti6Al4V alloy, the laser cladding (LC) technology characteristics of metallurgical bonding were used to prepare cubic boron nitride/Ti6Al4V and Ni-plated cubic boron nitride/Ti6Al4V composite coatings on Ti6Al4V substrates in this paper. However, in the laser molten pool, it is difficult to retain the raw properties of cubic boron nitride particles under laser radiation. Both composite coatings were analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The microstructures and interface bonding between cubic boron nitride particles and the Ti6Al4V matrix were examined using SEM, and the wear resistance and the worn track morphology of the composite coatings were evaluated using the ball-on-disc wear test and step profiler (WTM-2E). The results indicated that the Ni-plated cubic boron nitride/Ti6Al4V composite coating showed fewer thermal defects in comparison with the cubic boron nitride/Ti6Al4V coating. The Ni plating on the surface of cubic boron nitride particles was able to avoid the generation of thermal cracking of the cubic boron nitride particles in the composite coating. The TiN reaction layer was formed between the cubic boron nitride particles and Ti6Al4V matrix, which effectively prevented the further decomposition of the cubic boron nitride particles. The XRD and XPS results confirmed that the TiN reaction layer formed between the cubic boron nitride particles and Ti6Al4V. The Ni plating on the surface of the cubic boron nitride particles was also beneficial for increasing the wear resistance of the composite coating.