| As a high-precision,low-power,long-life inertial navigation device,hemispherical resonator gyroscope(HRG)is widely used in various fields such as inertial navigation,weapon equipment,and deep space exploration.The hemispherical harmonic oscillator ensures the working reliability of the hemispherical resonator gyroscope with its excellent characteristics of high Q value and low frequency difference.The impact of its metallization coating and the quality of the film on its key characteristics is very important for the development of harmonic oscillators.In this paper,the following researches on its coating process and key characteristics have been carried out:First,this paper established a two-dimensional Monte Carlo model based on the dynamic lattice method to simulate the film growth process.The changes of key parameters in the film growth process with time and the effects of different deposition rates and temperatures on the morphology of the film are studied.The results show that the crystal grains grow rapidly in the initial stage of film growth,the number of crystal grains decreases rapidly,and the average grain diameter increases rapidly.After that,it remained basically stable.As the deposition rate and temperature increase,the number of islands on the plane gradually decreases,and independent islands are connected to form a larger island.The result is consistent with the theoretical model.Secondly,the DC magnetron sputtering method was used to deposit nano-Al film on the quartz glass substrate,and the characteristics of the film deposited with different process parameters were tested and characterized.The results show that the deposition rate of Al film on the substrate increases with the increase of sputtering power,and first increases and then decreases with the increase of chamber pressure.The experiment is consistent with the simulation results.The grain size of the deposited film increases with the increase of the sputtering power,and first increases and then decreases with the increase of the chamber pressure.The film deposited under the conditions of 100 W and 1.6Pa is the most uniform and dense.The surface of the prepared Al film is relatively flat,and the process conditions have little effect on the Surface roughness of the film.The tensile test showed that the peel strength of the film reached 2.81N/cm.Finally,the magnetron sputtering coating experiment of the hemispherical fixture and the resonator was carried out,and the thickness of the patch was tested.The results show that the film thickness of the inner and outer hemispheres gradually decreases from the top of the sphere to the lip.The film thickness uniformity of the inner spherical surface at different latitudes is better than that of the outer spherical surface,the uniformity of the inner and outer films deposited by the multi-degree-of-freedom sputtering experiment is better than that of the zero-degree-of-freedom coating experiment.The coating experiment reached 3.77% and 14.24%.The frequency difference and Q value of the harmonic oscillator before and after coating are tested.The results show that the frequency difference before and after coating is 0.0408 Hz and 0.0409 Hz,with a change of 0.0001 Hz.The thickness uniformity of the inner spherical surface is high and the uniformity of the curved surface is controlled within 4%,and the quality defects caused by it have little effect on the frequency difference.The Q value before and after coating is attenuated by 56.78%.The thickness of the gold film of 100 nm has a greater impact on the Q value of the resonator,which greatly reduces the Q value. |
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