Method of forming metal, ceramic or ceramic/metal layers on inner surfaces of hollow bodies using pulsed laser deposition

Abstract

A pulsed laser deposition (PLD) process is used for forming a functional metal, ceramic, or ceramic/metal layer on an inner wall of a hollow body. Simultaneously with the deposition process, a thin-film laser treatment is carried out, whereby a laser beam impinges on the coating layer as it is being formed to achieve a rapid heating followed by a rapid cooling and solidification of the deposited coating layer. In this context, the energy and material flux densities are prescribed and controlled as a function of the spacing of the condensation region from the substrate surface. Laser pulses having an energy of 1 to 2 Joules and a pulse repetition rate of 10 to 50 Hz are used. The pulse duration as well as the residual gas atmosphere in the vacuum deposition chamber are controlled so that the generated plasma flux forms the desired layered grain structure, namely a glassy amorphous structure, a columnar structure, or a polycrystalline structure. The coating or target material can be made of a conducting material and/or an insulating material. By continuously or discretely varying process parameters, it is possible to form graded layer coating systems having properties that vary through the thickness of the coating.

Dependencies are inferred from the claim text.