Testing of the B₄C Protective Coating Under Irradiation with Intense Plasma Flows at the QSPA-T Facility

The influence of pulsed plasma irradiation on a boron carbide (B₄C) coating using the QSPA-T setup was investigated. The duration of the rectangular plasma pulses was 0.5 ms, with intervals between pulses of 5 to 10 min. The maximum power density in the middle of the plasma flow reached 1 GW/m². The thickness of the coating at various surface locations ranged from 20 to 40 μm. The modification of the surface layers and the transformation of the coating at elevated temperatures during the pulsed plasma irradiation process over four consecutive series of pulses are described. It was shown that the boron carbide coating withstood a complete cycle of tests under irradiation with 100 plasma pulses at a maximum power density of 1 GW/m². No significant damage was detected on the surface of the coating, and the layer remaining after the tests maintained the crystalline structure of B₄C throughout the irradiation zone to a depth of at least 2 μm.