| This paper reported the design and synthesis of TiB2/Si3N4 and TiB2/c-BN multilayered coatings with nanoscale bilayer period on Si (100) and Al2O3(111) using ultrahigh vacuum on magnetron sputtering and IBAD. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to investigate layered and crystal structure of the coatings. The mechanical properties of the multilayered coatings including hardness, elastic modulus and adhesion were measured by profiler (XP-2) and Nano Indenter XP system. Our purpose is to insight into the significance of the different process parameters, such as annealing temperature, influence on the structure and mechanical properties of the multilayered coatings and obtain better mechanical properties.Based on data of monolithic coatings, TiB2/Si3N4 multilayered coatings have been synthesized by ultra-high vacuum ion beam assisted deposition (IBAD) on Si (100) and Al2O3 (111). Orthogonal experiment was carried to optimize the spraying parameter sand employed to investigate the effect of modulation ratio, modulation period, thickness of buffer layer and temperature of substrate. The nanoscale multilayered modulation structure and clear interface were confirmed by SEM and low-angle XRD. When the base was heated up and the multilayer with modulation period of 11.8 nm, displays the highest hardness of 36.4 GPa, and lowest internal stress, fracture resistance, and residual stress are all improved compared to the monolithic coatings. At the same time, high-angle XRD patterns show a marked polycrystalline structure with the strong mixture of TiB2 (100), Si3N4 (110), TiB2 (001) and Si3N4 (101), which is one reason of the hardness enhance.the Orthogonal experiment show the all of property are greatly improved. The main foctor that influence property is modulation period. The best modulation period of multilayered coatings cased interaction effect and maked the diversity crystallize was the main reason of improving nano hardness.Choose TiB2 and c-BN as monolithic materials, a series of TiB2/c-BN multilayered coatings have been synthesis by the RF magnetron sputtering at 225℃, and the influence of modulation periods, thickness ratio and working pressure on microstructure and mechanical properties of the coatings were investigated. The low-angle XRD pattern and SEM indicated a well-defined composition modulation and layer structure of the multilayered coating. In the process, the main factors were working pressure and bias. the best parameters:base temperature is 225℃, modulation period of 24 nm, tTiB2:tc-BN=13:1. Besides all multilayers possess higher hardness and elastic modulus than the monolithic coatings, the residual stress of the multilayers is also improved. The hardness and elastic modulus with maximum values of 42GPa and 504 GPa respectively. Especially, we studied the structure and property in high temperture, The hardness of multilayered coating still achieved above 32GPa. TiB2/c-BN multilayered coating's internal stress, friction coefficient, and fracture resistance were greatly improved.Few of academic paper on relationship between microstrure and properties of nanoscale TiB2/Si3N4 and TiB2/c-BN multilayered coatings have been reported in recent literatures. The research shows that orthogonal experiment was carried to optimize the spraying parameters to synthesized the best mechanical properties TiB2/Si3N4 multilayered by IBAD, and the best mechanical properties TiB2/c-BN multilayered can be synthesized by magnetron sputtering. In addition, to synthesis the high hardness, high elastic modulus, well adhesion and low residual stress and obtain the optimal technologic parameter, the analysis on the hardness enhance of the different structure system of TiB2/Si3N4 and TiB2/c-BN multilayer is discussed. Therefore, these studies have great potential as protective coatings, enhancing the hardness of the multilayer system, improving the performance of material surface, exploiting the new superhardness materials and expanding the application of industry on nanoscale multilayered coatings.
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