Abstract: Simple and complex “heat pipes” are fabricated using solid, freeform fabrication techniques. The heat pipes are surrounded by materials having other desired physical properties such as coefficient of thermal expansion, stiffness, etc. According to one embodiment of the invention, high thermal conductivity foils, composed of materials such as copper or aluminum, are sandwiched between materials having desirable thermal expansion properties to provide components having high cooling rates and dimensional stability. Layer thickness, alloy and thickness are variable, and can be further altered by stacking varying numbers of layers of a given composition prior to incorporating a second material. The object size and design can range from a few millimeters on a side up to large components designed to manage heat flow in entire assemblies.

Abstract: A continuous, single-step, low-temperature process combines metal coating with the splicing of fibers, producing a single, continuous low-cost process for embedding fibers in metal, and/or the splicing of fibers with a joint featuring uniform composition and high strength requiring no additional adhesives. The method can be used to create terminations for cables, or it can be used as a method of splicing or joining optical fibers by positioning the ends of the two fibers under the foils, so that they abut prior to creating the bond. The consolidation material may be provided in sheets, with or without fiber-locating grooves or, alternatively, droplets may be used. In the preferred embodiment, ultrasonic vibrations are used as the source of consolidation energy. A range of metals are suited to the process, including aluminum, copper, titanium, nickel, iron and their alloys as well a numerous other metals of more limited structural utility.

Abstract: This invention improves upon existing approaches by providing a method for improving the uniformity of additive manufacturing processes of the type wherein material increments are consolidated to produce a three-dimensional object. According to one aspect of the invention, the method comprises the steps of tacking an increment during the method to minimize creep, then fully consolidating that increment to the underlying material. According to a different aspect of the invention, the method includes a step of steering the welding head or the feeding of the increments to ensure that the relative orientation of the contact line of the welding head as defined by the lowest surface is parallel to the central axis. As yet a further aspect of the invention, a different method includes a step of placing the increment so as to minimize the ratio of deformed to undeformed material. Such placement may be carried out manually over automatically.

Abstract: A system and a method of fabricating a three-dimensional object on a substrate includes adding material layers incrementally and consolidating the layers by using ultrasonic vibrations and pressure. The layers are placed in position to shape the object by a material feeding unit, and they come in various forms, including flat sheets, segments of tape, strands of filament or single dots of material. The material may be plastic or metallic, and composition may vary discontinuously or gradually from one layer to the next, creating a region of functionally gradient material. The invention permits the construction and repair of dense objects, including fiber-reinforced composites and aerospace structures. Excess material may be removed one or more layers are bonded, including following end of the process after the final object is fabricated.

Abstract: Machine tools combine material addition via ultrasonic object consolidation and subtractive techniques for imparting high-dimensional accuracy to a finished object. A material supply and feeder, ultrasonic horn, and feedstock cutting device are integrated with a material removal subsystem preferably including a cutting tool and an excess material removal system. Any metal, plastic or composite material suitable for ultrasonic joining may be employed as a feedstock, and these material may assume the form of tapes, sheets, wires, filaments, dots or droplets, with the feeding and material cutting components being designed for the specific feedstock employed. The cutting tool for excess material removal, may be a knife, drill/mill, grinding tool, or other tool capable of accurately cutting the external contour of a cross section of the part being built, and for removing excess feedstock remaining following the application process.

Abstract: Friction heating and bonding are used to consolidate sequentially applied metals, plastics or composites to previously deposited material so as to form a bulk deposit in a desired shape. Monolithic or composite sheets, tapes and filaments can be consolidated using the approach. A system according to the invention includes a source of friction; a mechanism for applying a forging load between a feedstock power supply and a work surface; a work-head, which may have various configurations depending on the geometry of the feedstock to be used; a material feeding system; and a computer-controlled actuation system which controls the placement of material increments added to an object being built. A computer model of the object to be built is used to generate commands to produce the object additively and automatically. The approach provides a solid, freeform fabrication technique that requires no tooling, operates in the solid state, and creates a bond directly at the faying surfaces (i.e.

Abstract: Resistance heating, preferably with applied pressure, is used to consolidate incremental volumes of material to produce a desired object in accordance with a description thereof. The joining of the material increments may occur in the solid state, liquid state, or ‘mushy’ state in conjunction an atomically clean faying surface between the increments without melting the material in bulk. Residual stresses are minimized, particularly in metal objects, by imposing a compressive residual stress on the surface of each deposited layer or increment, which offsets all or a portion of the tensile stress created as the next layer deposited above it cools. In terms of apparatus, a moving cathode is used to ensure uniform electrical current flow in an object with constantly changing geometry.

Abstract: A continuous, single-step, low-temperature process combines metal coating with the splicing of fibers, producing a single, continuous low-cost process for embedding fibers in metal, and/or the splicing of fibers with a joint featuring uniform composition and high strength requiring no additional adhesives. The method can be used to create terminations for cables, or it can be used as a method of splicing or joining optical fibers by positioning the ends of the two fibers under the foils, so that they abut prior to creating the bond. The consolidation material may be provided in sheets, with or without fiber-locating grooves or, alternatively, droplets may be used. In the preferred embodiment, ultrasonic vibrations are used as the source of consolidation energy. A range of metals are suited to the process, including aluminum, copper, titanium, nickel, iron and their alloys as well a numerous other metals of more limited structural utility.

Abstract: Machine tools combine material addition via ultrasonic object consolidation and subtractive techniques for imparting high-dimensional accuracy to a finished object. A material supply and feeder, ultrasonic horn, and feedstock cutting device are integrated with a material removal subsystem preferably including a cutting tool and an excess material removal system. Any metal, plastic or composite material suitable for ultrasonic joining may be employed as a feedstock, and these material may assume the form of tapes, sheets, wires, filaments, dots or droplets, with the feeding and material cutting components being designed for the specific feedstock employed. The cutting tool for excess material removal, may be a knife, drill/mill, grinding tool, or other tool capable of accurately cutting the external contour of a cross section of the part being built, and for removing excess feedstock remaining following the application process.