Particles inside a composite material or defects in a crystalline material lead to discontinuity in the electrical and acoustical properties.

The discontinuity in the dielectric permittivity enhances the electrical field at the grain boundaries and forces the discharge channels to the boundaries. The sudden expansion of the created plasma produces a shock wave with local pressures up to 10’000bar. The interaction of a shock wave and an acoustical discontinuity concentrate tensile stress at these interfaces.

The SELective FRAGmentation technology of SELFRAG uses these effects to liberate material along the material boundaries, to weaken material along particle boundaries or to diminish the size of material without introducing contamination.

Field enhancement simulation result of material in a process vessel

Photograph of streamers during material treatment