Trial Implementation of TiN Surface Coating for a Main Piston Towards Reducing the Opening Time for a Diaphragmless Driver Section

In this study, we have performed TiN coating for a free piston to decrease the abrasion resistance between the free piston and a housing, consisted of a main piston. The thickness of the TiN layer on the surface is 2 μm. The opening time of the main piston is measured by using the surface-coated free piston. As a consequence, the opening time of the main piston is achieved 500 μs for 2 mm stroke. Additionally, the shock wave has been generated in the glass tubes with 2, 3, and 4 mm diameter to confirm the shock wave propagation. The shock wave measurements are performed at the several points along the axial direction of the tube by using laser differential interferometer. Consequently, the shock wave propagation is confirmed by using the surface-coated free piston. Moreover, the experimental efficiency is drastically improved especially at the initial experimental process. However, TiN coating partly disappeared by repeated use.