Tufts University

Northeastern University

Charalabos Doumanidis

Teiichi Ando

Norbert Johnson

Precursor-based methods for the production of metal-matrix composite (MMC) coatings on steel and aluminum substrates for improved wear, corrosion and oxidation resistance have been made. Wire and surface precursors are deposited on the substrate by controlled thermal processing using plasma-arc, laser and high-density infrared radiation. The temperature distribution during the formation for coating is controlled by a real tine adaptive control method. The wire precursors produced by continuous pressure infiltration of SiC or mullite fiber with aluminum were used. Steel substrates double-layer plated with binary metals including nickel and aluminum are also thermal-processed to in-situ produce compound such as nickel aluminide coatings.

Process of forming a composite coating on a substrate

A method and apparatus for producing a three-dimensional part from a plurality of planar layers using an ultrasonic welder. A sheet of planar material is placed on the partial part and ultrasonically welded, with the first sheet placed on a base. The sheet is cut to the shape of the partial part. The process of placing of the sheet materials on the partial, welding, and cutting of the two-dimensional contour layer is continued until part is complete. In a preferred embodiment, the three-dimensional part has layers of different material. The materials can be layers of incompatible materials for ultrasonic welding in which voids are created through interposed non-compatible materials for ultrasonic welding, to allow ultrasonic welding of compatible material layers spaced by a sheet of incompatible material. In a preferred embodiment a component, such as a thermal actuator; a optical component; an internal sensor; a plurality of electronic elements, or a mechanical actuator for creating a actively deformable part, is introduced between layers of material of the part. The method described allows the introduction of components which are sensitive to manufacturing temperatures. A pressure mask applies pressure to the top layer as the layer is ultrasonic welded to the part. In a preferred embodiment, the elongated sheets of material are carried on a supply drum and moved over the partial part using a feed system having the supply drum and a take-up drum.

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Vienna, VA, United States of America

Charalabos Doumanidis