초록 ▼

A dense or porous coating of material is deposited onto a substrate by forcing a colloidal suspension through an ultrasonic nebulizer and spraying a fine mist of particles in a carrier medium onto a sufficiently heated substrate. The spraying rate is essentially matched to the evaporation rate of th

A dense or porous coating of material is deposited onto a substrate by forcing a colloidal suspension through an ultrasonic nebulizer and spraying a fine mist of particles in a carrier medium onto a sufficiently heated substrate. The spraying rate is essentially matched to the evaporation rate of the carrier liquid from the substrate to produce a coating that is uniformly distributed over the surface of the substrate. Following deposition to a sufficient coating thickness, a single sintering step may be used to produce a dense ceramic coating. Using this method, coatings ranging in thickness from about one to several hundred microns can be obtained. By using a plurality of compounds in the colloidal suspension, coatings of mixed composition can be obtained. By using a plurality of solutions and separate pumps and a single or multiple ultrasonic nebulizer(s), and varying the individual pumping rates and/or the concentrations of the solutions, a coating of mixed and discontinuously graded (e.g., stepped) or continuously graded layers may be obtained. This method is particularly useful for depositing ceramic coatings. Dense ceramic coating materials on porous substrates are useful in providing improved electrode performance in devices such as high power density solid oxide fuel cells. Dense ceramic coatings obtained by the invention are also useful for gas turbine blade coatings, sensors, steam electrolyzers, etc. The invention has general use in preparation of systems requiring durable and chemically resistant coatings, or coatings having other specific chemical or physical properties.

대표청구항 ▼

1. A method for applying a thin coating material onto a substrate, said method comprising:(1) suspending colloidal ceramic material particles of average particle size of less than 10 microns in size in a solvent to form a colloidal suspension; (2) heating substrate to produce a heated substrate; (3)

1. A method for applying a thin coating material onto a substrate, said method comprising:(1) suspending colloidal ceramic material particles of average particle size of less than 10 microns in size in a solvent to form a colloidal suspension; (2) heating substrate to produce a heated substrate; (3) ultrasonically nebulizing said colloidal suspension onto said heated substrate to deposit a particle layer on said substrate, said heated substrate controlled to have a surface temperature less than the temperature at which said particles chemically decompose into simpler converted products; and (4) sintering said particle layer deposited in step (3), wherein said coating is deposited in a single dispersion step to produce a coating having a thickness between 1 and 250 microns.