The Process of Superdeep Penetration of High-Speed Metallic Particles into a Solid Body

The effects arising at the collision of a stream of metal particles 10–100 µm in size, moving at a speed of 1–3 km/s, with a solid target are explained. It is suggested that, at the instant of impact on the target, a particle loses some electrons and retains a positive charge for some time due to the presence of an oxide shell. The electron flux passing through the target at the impact instant generates an electromagnetic field. A particle with a charge of ~10^–9 C, having penetrated a solid target, presses on the channel wall with a force of ~500 MPa and moves in it under the action the forces caused by the target material polarization. The combination of high pressure and displacement leads to a significant decrease in the particle–wall friction force. The proposed hypothesis, if confirmed, may help to find ways to protect spacecraft electronic devices from impacts caused by streams of fast dust particles.