电工技术学报2024，Vol.39Issue(19)：5947-5957,11.DOI:10.19595/j.cnki.1000-6753.tces.231406
滑动电接触梯度功能材料电枢熔化磨损特性仿真研究
Study on Melting and Wear Characteristics of Sliding Electric Contact Functionally Gradient Material Armature
摘要
Abstract
The electromagnetic railgun is a novel kinetic energy weapon concept that utilizes controllable and precise electromagnetic forces generated by electromagnetic devices to propel the armature and ammunition in a linear trajectory.In comparison to traditional powder launch systems,electromagnetic railguns must endure high currents and substantial contact pressures during the launch process.Due to the initially low movement speed of the armature,the Joule heat primarily causes surface melting and wear.This leads to a concentrated deposition of the metal liquefaction layer on the track surface,resulting in significant deterioration of the electrical contact with the guide rail in this section.These demanding working conditions impose stringent requirements on the electromagnetic railgun materials,necessitating high-temperature resistance,high yield strength,and high hardness.Typically,the contact surface between the solid armature and the launch track is prone to melting and wear due to the combined effects of Joule heat and frictional heat.Subsequently,the metal liquefaction layer cools and deposits onto the track surface.After repeated launches,the thickness of the deposited layer on the track surface increases or even detaches,leading to reduced track surface smoothness,alterations in track spacing,and interior contamination.Consequently,the service life and launch controllability of the electromagnetic railgun are compromised. Functionally gradient material exhibit continuously changing physical properties along the thickness direction.This characteristic enables them to harness the benefits of various materials while avoiding the risk of cracking and fracturing under high temperature and pressure conditions.This article proposes a method for enhancing the armatures'surface melting point,reducing their melting wear rate,and extending the rails'service life in electromagnetic orbit launchers through the use of gradient material armatures.By employing multi-physical field coupling simulation,suitable gradient material armatures were identified to investigate their melting wear characteristics.Initially,a"flat plate"layered gradient material model was adopted.The mechanical,thermal,and electrical properties of each composite material layer were expressed as functions of the volume fraction of the functional material,using a volume fraction exponential expression.Subsequently,utilizing COMSOL Multiphysics,the simulation considered the armature's melting during the initial stage,influenced by Joule heat generated by current flow resistance and contact resistance between the armature and rail surface. Results indicate that chromium is the most suitable functional material for forming gradient material armatures when combined with an aluminum matrix.It is followed by niobium and molybdenum.On the other hand,copper-based functional gradient material armatures exhibit weaker resistance to melting wear.In the case of armatures composed solely of functional materials,molybdenum and copper-coated armatures demonstrate stronger resistance to melting wear,followed by chromium-coated armatures.Niobium-coated armatures display the weakest resistance to melting wear.The simulation experiment will be applied to the production and testing of gradient material armatures.The simulation outcomes hold significant guiding implications for gradient material armature testing.关键词
电磁轨道炮/梯度功能材料电枢/熔化磨损/仿真分析Key words
Electromagnetic railgun/functionally gradient material armature/melting wear/simulation analysis分类
军事科技引用本文复制引用
邹昕阳,陈立学,王增基,许璇,张智榣..滑动电接触梯度功能材料电枢熔化磨损特性仿真研究[J].电工技术学报,2024,39(19):5947-5957,11.基金项目
国家自然科学基金资助项目(92266301). （92266301）
