Abstract:
A product in which at least a portion of the product has a nanocrystalline microstructure, and a method of forming the product. The method generally entails machining a body in a manner that produces chips consisting entirely of nano-crystals as a result of the machining operation imposing a sufficiently large strain deformation. The body can be formed of a variety of materials, including metal, metal alloy and ceramic materials. Furthermore, the body may have a microstructure that is essentially free of nano-crystals, and may even have a single-crystal microstructure. The chips produced by the machining operation may be in the form of particulates, ribbons, wires, filaments and/or platelets. The chips are then used to form the product. According to one aspect of the invention, the chips are consolidated to form the product, such that the product is a monolithic material that may contain nano-crystals. According to another aspect of the invention, the chips are dispersed in a matrix material, such that the product is a composite material in which the chips serve as a reinforcement material.
Abstract:
A method by which consolidated articles can be produced from nanocrystalline materials to have mechanical properties that can be improved through thermal treatment. The method entails machining a body to produce polycrystalline chips having nanocrystalline microstructures, and then consolidating the chips to form a consolidated article having mechanical properties that exceed that of the body from which the chips were formed. In particular, consolidation of nanocrystalline chips formed by machining a supersaturated solid-solution body causes precipitation of a fine dispersion of precipitates in the consolidated article, with the potential for certain properties to even improve during consolidation or subsequent thermal treatment of the consolidated article.
Abstract:
A tool holder assembly (10) and method for intentionally inducing modulation in a machining process. The tool holder assembly is configured for mounting in a tool block (22) on a machining apparatus and includes a tool holder body (20) configured to be secured to the tool block of the machining apparatus, a tool holder (14) mounted on the tool holder body and configured for securing a cutting tool (12) thereto, an a device (24) for imposing a superimposed modulation on the tool holder so as to move the cutting tool relative to the tool holder body and thereby relative to the tool . The tool holder assembly is useful in a process for producing chips having a desired shape and size, and particularly to a method of controllably producing nanocrystalline chips.
Abstract:
A process by which nanostructured monolithic bodies can be produced in a single continuous operation, as opposed to multi-stage deformation processing. The process generally entails continuously producing a chip (24) having a nanostructured microstructure by engaging a solid body (10) with a cutting edge (18) of a tool while the solid body (10) and the cutting edge (18) move relative to each other, and simultaneously extruding the chip (24) in the immediate vicinity of the cutting edge (18), such as with a constraining member (16), as the chip (24) is separated from the solid body (10) by the cutting edge (18) to continuously plastically deform the chip (24) and produce a nanostructured monolithic body (26) immediately downstream of the cutting edge (18). The shape and size of the chip (24) can be simultaneously controlled by the extrusion process so that the nanostructured monolithic body (26) has a predetermined geometry. The nanostructured monolithic body (26) can be in the form of a product suitable for immediate use, or undergo further processing to yield a product.
Abstract:
A method for producing articles containing nanocrystalline microstructures, and particularly to a method of controllably producing nanocrystalline chips with a desired shape and size. The method generally entails machining a body with a cutting tool to produce polycrystalline chips having nanocrystalline microstructures while superimposing modulation on the cutting tool so as to move the cutting tool relative to the body being machined and cause instantaneous and periodic separation between the cutting tool and the body at a point of contact between the cutting tool and the body, wherein each separation between the cutting tool and the body yields a chip. In this manner, the shapes and sizes of the chips are determined at least in part by the modulation cycle, and particularly the length of time the cutting tool is engaged with the body being machined.
Abstract:
Method of producing products having at least a portion thereof with a nanocrystalline microstructure . The method entails machining a body to produce a polycrystalline chip having a nanocrystalline microstructure. The chips produced by the machining operation may be in the form of particulates, ribbons, wires, filaments and/or platelets. The chips may be consolidated (with or without comminution) to form a product, such that the product is essentially a nanocrystalline monolithic material consisting essentially or entirely of nano-crystals, or of grains grown from nano-crystals . Alternatively, the chips may be dispersed in a matrix material, such that the product is a composite material in which the chips are dispersed as a reinforcement material. According to a particular aspect, a monolithic article can be formed entirely from a single chip by deforming the chip and/or removing material from the chip.