A process for valve seal face strengthening by vapor deposition

Abstract

This invention relates to the field of metal surface strengthening technology and discloses a vapor deposition process for strengthening valve sealing surfaces, comprising: heating a valve substrate in a vacuum chamber; introducing a precursor gas to construct a vapor deposition environment; monitoring pressure fluctuation signals in the near-wall region of the sealing surface to determine the transient pressure drop rate; comparing the transient pressure drop rate with a pressure transition threshold to determine the vapor phase depletion stage and identify a low-collision-section region; applying a radio frequency negative bias voltage to the valve substrate during the vapor phase depletion stage to accelerate ions through the low-collision-section region, with ions impacting the crystal nuclei of the sealing surface with peak kinetic energy, inducing crystal dislocations. This invention utilizes the ballistic penetration mechanism of the vapor phase depletion interface to prevent ions from scattering in the vapor phase and achieve deep energy injection, suppressing the longitudinal growth of columnar crystals, forming an equiaxed crystal structure, and enhancing the density of the strengthening layer and the interfacial bonding force.

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