Patents by Inventor Srinivasan Chandrasekar
Srinivasan Chandrasekar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7587965Abstract: A tool holder assembly and method for intentionally inducing modulation in a machining process. The tool holder assembly is configured for mounting in a tool block on a machining apparatus and includes a tool holder body configured to be secured to the tool block of the machining apparatus, a tool holder mounted on the tool holder body and configured for securing a cutting tool thereto, and a device 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.Type: GrantFiled: May 3, 2006Date of Patent: September 15, 2009Assignee: Purdue Research FoundationInventors: James B. Mann, Srinivasan Chandrasekar, Walter Dale Compton
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Publication number: 20080138163Abstract: 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 having a nanostructured microstructure by engaging a solid body with a cutting edge of a tool while the solid body and the cutting edge move relative to each other, and simultaneously extruding the chip in the immediate vicinity of the cutting edge, such as with a constraining member, as the chip is separated from the solid body by the cutting edge to continuously plastically deform the chip and produce a nanostructured monolithic body immediately downstream of the cutting edge. The shape and size of the chip can be simultaneously controlled by the extrusion process so that the nanostructured monolithic body has a predetermined geometry. The nanostructured monolithic body can be in the form of a product suitable for immediate use, or undergo further processing to yield a product.Type: ApplicationFiled: December 6, 2006Publication date: June 12, 2008Applicant: PURDUE RESEARCH FOUNDATIONInventors: Wilfredo Moscoso, James B. Mann, M. Ravi Shankar, Srinivasan Chandrasekar, Walter Dale Compton
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Patent number: 7294165Abstract: 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.Type: GrantFiled: January 30, 2004Date of Patent: November 13, 2007Assignee: Purdue Research FoundationInventors: Srinivasan Chandrasekar, Walter D. Compton, Thomas N. Farris, Kevin P. Trumble
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Publication number: 20060278308Abstract: 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.Type: ApplicationFiled: May 3, 2006Publication date: December 14, 2006Applicant: Purdue Research FoundationInventors: M. Shankar, Srinivasan Chandrasekar, W. Compton, Alexander King, Kevin Trumble
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Publication number: 20060248980Abstract: A products having at least a portion thereof with a nanocrystalline microstructure, and methods of producing such products. The method generally 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.Type: ApplicationFiled: May 3, 2006Publication date: November 9, 2006Applicant: Purdue Research FoundationInventors: James Mann, Srinivasan Chandrasekar, Walter Compton
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Publication number: 20060251480Abstract: A tool holder assembly and method for intentionally inducing modulation in a machining process. The tool holder assembly is configured for mounting in a tool block on a machining apparatus and includes a tool holder body configured to be secured to the tool block of the machining apparatus, a tool holder mounted on the tool holder body and configured for securing a cutting tool thereto, and a device 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.Type: ApplicationFiled: May 3, 2006Publication date: November 9, 2006Applicant: Purdue Research FoundationInventors: James Mann, Srinivasan Chandrasekar, Walter Compton
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Publication number: 20060243107Abstract: 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.Type: ApplicationFiled: May 3, 2006Publication date: November 2, 2006Applicant: Purdue Research FoundationInventors: James Mann, M. Shankar, Srinivasan Chandrasekar, W. Compton, Wilfredo Moscoso
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Publication number: 20050167008Abstract: 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.Type: ApplicationFiled: January 30, 2004Publication date: August 4, 2005Applicant: PURDUE RESEARCH FOUNDATIONInventors: Srinivasan Chandrasekar, Walter Compton, Thomas Farris, Kevin Trumble
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Patent number: 6706324Abstract: 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.Type: GrantFiled: October 27, 2001Date of Patent: March 16, 2004Assignee: Purdue Research FoundationInventors: Srinivasan Chandrasekar, Walter D. Compton, Thomas N. Farris, Kevin P. Trumble
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Patent number: 6581074Abstract: Directory synchronization is disclosed. A synchronization logic synchronizes a first directory and a second directory. The logic has one or more synchronization capabilities: a dampening capability, an identifier mapping capability, and a checksum capability. The dampening capability prevents changes that originate from the second directory that have already been synchronized to the first directory from being synchronized back to the second directory. The identifier mapping capability uses a table that maps a unique identifier of each record of the first directory with a unique identifier of a corresponding record of the second directory. Records that are moved within a directory can then be located. The checksum capability uses a checksum for each record in one of the directories, to efficiently detect changes.Type: GrantFiled: October 6, 2000Date of Patent: June 17, 2003Assignee: Microsoft CorporationInventors: Felix W. Wong, Srinivasan Chandrasekar
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Publication number: 20020150496Abstract: 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.Type: ApplicationFiled: October 27, 2001Publication date: October 17, 2002Inventors: Srinivasan Chandrasekar, Walter D. Compton, Thomas N. Farris, Kevin P. Trumble
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Patent number: 6385500Abstract: The present invention relates to an improved servomechanism for regulating the spark gap in micro electrical discharge machining (micro-EDM). The present invention utilizes a hybrid two actuator servo system for positioning the micro-EDM electrode. The hybrid system comprises a fast, easily controllable, short stroke actuator (such as a piezoelectric actuator) for good instantaneous response, and a second, slower actuator for positioning the fast actuator and for providing the required long stroke. This allows the slower actuator to “feed” the electrode into the work-piece utilizing its long stroke, and the fast, short stroke actuator to respond quickly to instantaneous variations in the spark gap, such as short circuits.Type: GrantFiled: April 16, 1999Date of Patent: May 7, 2002Assignee: Cummins Engine Company, Inc.Inventors: Rajadasa R. Hebbar, Ramanujam Ramabhadran, Srinivasan Chandrasekar