Kinetics of plasma-assisted boriding

A study of boron condensation kinetics on steel in DC plasma discharge, using a mixture of BCl3–H2 is presented. The aim of the study is to investigate the kinetics of this reaction in a temperature range of 750–800 °C and at a constant pressure of 520–550 Pa. Assuming a laminar flow of the gas mixture and regarding our experimental equipment as a tubular, non-isothermal reactor, we described the distribution of the concentration of boron trichloride and hydrogen chloride along the central cathode. Pictures of the cathode surface show a gradual formation of boron in the direction of flow of the gas mixture. At the same time, a maximum of the hydrogen chloride concentration passes along the surface of the cathode. The rate of the process is directly proportional to the initial concentration of boron trichloride.