Numerical simulation and experiment of uniform growth of MPCVD diamond coating
Based on the microwave plasma module of multiphysics simulation software COMSOL Multiphysics,a nu-merical model of hydrogen plasma inside a MPCVD reactor was built.The effect of different height differences △h between the circular molybdenum support added on the outer side of the substrate and the substrate on the plasma distri-bution at the surface of the substrate was investigated.The uniformity of plasma distribution was quantitatively ana-lyzed by coefficient of variation,and the microstructure of diamond coating surface was characterized by SEM.The res-ults show that when △h=0 mm,the uniformity of plasma distribution is the best,the coefficient of variation is 3.998％,and the uniformity of grain distribution and size of diamond coating is significantly improved compared with that without molybdenum support.When △h＜0 mm,the uniformity of plasma distribution increases with the increase of △h,and the coefficient of variation decreases from 10.265％to 3.998％.When △h＞0 mm,the uniformity of plasma distribu-tion does not increased but decreases,and the coefficient of variation increases to 10.048％.In addition,when △h=-2.0 mm,the plasma density on the substrate surface decreases by about 20％,which is not conducive to the growth of dia-mond coating.
国家科技期刊平台
NSTL
万方数据
