Influence of material type and surface roughness of substrate on boronization and its performance. (May 2021)

• Record Type: Journal Article
• Authors: Tian, Xiaorang; Meng, Chuizhou; Zhao, Xin; Liu, Bing; Zhao, Guanchao; Nie, Ge; Yang, Guoyun; Zhang, Guosong; Han, Peide
• Is Part Of: Vacuum. Volume 187(2021)
• Publication Date: 2021-05
• Subjects: Boronization -- Boron film -- Surface roughness -- Substrate material -- Impurity control; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2021.110091
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Diborane (B2 H6 ) glow discharges were carried out for the study of influence of material type and surface roughness of substrate on the boronization and its plasma performance. We found that for the stainless steel (SS), the surface roughness should be smaller than 0.8 μm with an optimal value of 0.4 μm, in order to reach a maximum binding force of 320 N/m. The effective boron (B) film growth by using the same parameter was also realized on both the surface of SS and Si substrate, but not on the Cu substrate, mainly due to the easy enrichment of O element on Cu surface through formation of the B–O bond, which prevents subsequent formation of the B–B bond. After boronization, the partial pressure of residual gases of H2 O, CO2, CO and O2 was reduced by 47%, 80%, 56% and 33%, respectively, indicating the successful reduction of O and C impurities in the chamber. Highlights: This study first to examine the influence of material type and surface roughness of substrate on boronization. To obtain a good B film quality, the roughness of the SS should not exceed 0.8 μm, with an optimal values of 0.4 μm. B films could effectively grow on SS and Si substrates and difficult to realize effective growth on Cu substrate. B film could evidently reduce partial pressures of residual gases and get better vacuum condition. The study provides theoretical guidance with supporting data on the advanced boronization technique of Tokamak device.