Kinetic modelling of a N-2 flowing microwave discharge with CH4 addition in the post-discharge for nitrocarburizing treatments

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Carlos Daniel Diogo Matias Pintassilgo (Author) FEUP; Jaoul, C (Author) Other; Loureiro, J (Author) Other; Belmonte, T (Author) Other; Czerwiec, T (Author) Other

Journal

Title: Journal of Physics D: Applied Physics

Vol. 40 No. 12

Pages: 3620-3632

ISSN: 0022-3727

Publisher: Institute of Physics Publishing

Indexing

ISI Web of Knowledge - 17 Citations

Scopus - 18 Citations

Other information

Authenticus ID: P-004-9AD

DOI: 10.1088/0022-3727/40/12/011

Abstract (EN): A kinetic study is conducted to investigate the elementary processes scheme that produces methane decomposition as a small percentage of this gas is introduced downstream in the flowing afterglow of a nitrogen microwave discharge. For this purpose a self-consistent kinetic model is used for the discharge and corresponding afterglow including, besides the species associated with active nitrogen, such as vibrationally excited N-2(X (1)Sigma(+)(g), v) molecules, N-2(A(3)Sigma(+)(u)) and N-2(a' (1)Sigma(-)(u)) metastables and N(S-4) atoms, various hydrocarbons formed from methane decomposition, and other species produced in nitrogen-methane reactions. It is observed that CH4 is primarily dissociated in CH3 and CH2 in collisions with N-2(A), the stable hydrogen cyanide molecule HCN is formed at an intermediate stage of the process, HCN and CH2 give place to the formation of CN(X (2)Sigma(+)), and ultimately C atoms are produced by collisions of CN(X) with N atoms. The predicted concentrations so obtained are compared with experimental determinations of N and C atoms and of N-2(B (3)Pi(g)) and CN(B (2)Sigma(+)) states, these latter obtained from spectroscopic measurements.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13