Affiliations: [a] National Key Laboratory of Transient Physics, Nanjing
University of Science and Technology, Nanjing, Jiangsu, China
Correspondence:
[*]
Corresponding author: Chun-Sheng Weng, National Key Laboratory
of Transient Physics, Nanjing University of Science and Technology, Nanjing
210094, Jiangsu, China. Tel.: +86 25 8431 5932; Fax: +86 25 8431 5644; E-mail: wengcs@126.com
Abstract: In this paper we investigate the influence of different rail
coatings on melt-wave erosion (MWE) in block armatures. A two-dimensional
numerical model is developed and the finite difference method is used to
simulate the transient evolution of MWE. The results of numerical calculations
show a local concentration of current and joule heating at the interface, and
MWE occurs at the trailing corner of the block armature. Five different pure
metals are used as the rail coatings to improve the launching performance of
the railgun. Important electrical parameters of coatings are analyzed through
comparing the axial erosion distance and the vertical gap thickness. It is
observed that the coating materials with a higher electrical conductivity than
that of rail material are helpful to delay the spread of MWE. The results are
inspiring and contribute to apply the rail coatings to solid-armature railguns.
