Cerel (ceramic Technologies) Ltd.

Other

Leah Gal-Or

Nina Sezin

David Brandon

Rony Goldner

Albir A Layyous

Roni Goldner

Ala Pismany

Shai Gilboa

Leonid Perlin

Liudmila Cherniak

Sonia Liubovich

Ronen Lanir

Ludmilla Cherniak

Ron Goldner

Liudmilla Cherniak

Alex Barsky

Shay Gilboa

Sonja Liubovich

An improved method for depositing ferroelectric particles on a surface of a substrate to form films or stand-alone bodies. The improvement is based on electrophoretic deposition (EPD) of ferroelectric films by using a tri-functional phosphate ester additive having a concentration less than 10 volume percent in the EPD suspension, without the need for addition of a binder. The method includes preparation of the suspension by washing and dispersing ferroelectric particles, for example, commercially available PZT powder, in a polar solvent such as ethanol, followed by addition of the phosphate ester additive to the suspension, and an ultrasound treatment. The suspension is used in EPD of the ferroelectric particles on a prepared substrate. Following EPD, the green film is dried and sintered at high temperature. Visual and physical examination of stand alone and patterned PZT deposited films show excellent quality obtained in manufacturing a diversity of piezoelectric products, featuring exceptionally high green film uniformity, thickness distribution, and reproducibility to within &plusmn;2 microns for 20 micrometer film thickness. The phosphate ester additive functions by improving stabilization and control of suspension characteristics and properties during the electrophoretic migration process, and by improving desired dimensions, characteristics, and electrical properties of the deposited green film. Thin or thick ferroelectric films, either as stand alone products, or formed on geometrically demanding patterned or non-patterned substrates are produced by using the method. The improved method is applicable to different ferroelectric particulate materials and to different substrates used for manufacturing piezoelectric elements and devices, in a cost effective manner.

Method of electrophoretic deposition of ferroelectric films using a tri-functional additive and compositions for effecting same

A method of forming on an object a surface coating having a high mechanical strength and chemical and physical stability above 700&deg; C. is disclosed. The method comprises (a) electrophoretically depositing at least one surface coating material on a surface of the object for obtaining a green coating on the surface; and (b) infiltrating into and depositing onto the green coating at least one additional surface coating material by a gas-phase infiltration/deposition method, thereby forming a high performance surface coating, wherein, the at least one surface coating material and the at least one additional surface coating material are chemically and physically stable above 700&deg; C.

Method for forming high performance surface coatings and compositions of same

A method of depositing diamond particles on a surface of a substrate is provided. The method is effected by (a) charging the diamond particles by a positive charge to obtain positively charged diamond particles; and (b) electrophoretically depositing the positively charged diamond particles on the surface of the substrate, for obtaining a green diamond particles coat on the surface of the substrate.

Electrophoretic diamond coating and compositions for effecting same

An improved method for depositing ferroelectric particles on a surface of a substrate to form films or stand-alone bodies. The improvement is based on electrophoretic deposition (EPD) of ferroelectric films by using a tri-functional phosphate ester additive having a concentration less than 10 volume percent in the EPD suspension, without the need for addition of a binder. The method includes preparation of the suspension by washing and dispersing ferroelectric particles, for example, commercially available PZT powder, in a polar solvent such as ethanol, followed by addition of the phosphate ester additive to the suspension, and an ultrasound treatment. The suspension is used in EPD of the ferroelectric particles on a prepared substrate. Following EPD, the green film is dried and sintered at high temperature. Visual and physical examination of stand alone and patterned PZT deposited films show excellent quality obtained in manufacturing a diversity of piezoelectric products, featuring exceptionally high green film uniformity, thickness distribution, and reproducibility to within .+-.2 microns for 20 micrometer film thickness. The phosphate ester additive functions by improving stabilization and control of suspension characteristics and properties during the electrophoretic migration process, and by improving desired dimensions, characteristics, and electrical properties of the deposited green film. Thin or thick ferroelectric films, either as stand alone products, or formed on geometrically demanding patterned or non-patterned substrates are produced by using the method. The improved method is applicable to different ferroelectric particulate materials and to different substrates used for manufacturing piezoelectric elements and devices, in a cost effective manner.

Method of electrophoretic deposition of ferroelectric films using a

A method for electrophoretic deposition of ceramic particles as a green body shaped as a dental appliance, the method comprising the steps of (a) forming a suspension of the ceramic particles in a first polar solvent, the ceramic particles constituting at least about 5% of the first suspension by weight; (b) passing a direct electrical current through the first suspension, using a deposition electrode shaped as the dental appliance to form a green body; (c) coating the green body with glass particles; and (d) sintering the resultant coated body for obtaining a glass coated all-ceramic dental appliance.

Method of electrophoretic deposition of ceramic bodies for use in

A method of electrophoretic deposition of a ceramic green body. A ceramic powder is optionally washed with a polar solvent such as deionized water, dried, and suspended in a polar organic solvent in a proportion of at least 20% by weight. A positive surface charge is imposed on the suspended particles by conventional means such as ball milling or ultrasonic treatment. A green body is deposited on a cathode by passing a direct electric current of constant current density through the suspension. The density of the green body generally is at least 70% of theoretical. The density of the fired body generally is at least 98% of theoretical. A layered green body may be deposited by using several suspensions of differing global ceramic composition and depositing each microlayer in a different suspension.

Method of electrophoretic deposition of laminated green bodies

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Haifa, Israel

Leah Gal-Or