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Objective
A device and method for operation in a vacuum of a metal gas (MIG) welding system has been designed at Marshall Space Flight Center. In a vacuum, using existing systems, the plasma disperses rapidly and does not constrict the plasma arc, causing extinction of the arc. The proposed apparatus would generate plasma in an interior chamber where it would be maintained sufficiently dense to allow production of a bead on the workpiece. The invention is owned by NASA.
Description
The invention provides a pre-plasma cavity with two openings, one to accept an inert gas and a second allowing the plasma to exit; a structure to direct the plasma from the second opening to a welding cavity capable of being placed adjacent to a working surface and capable of accepting welding material. Means of regulating the flow rate of the inert gas is provided by use of needle or other precision valves, adjustable to vary the rate at which gas enters the pre-plasma chamber. Detailed information is contained in the patent number listed below. A copy is available at the address and telephone listed at the end of this document.
Benefits
The system prevents arc dispersion by containing and focusing the plasma to increase the heat transfer to the working surface, preventing the dispersion caused by the vacuum. It also regulates the flow rate by using available valves to govern the gas flow.
Current Capabilities
The system provides for MIG welding in the environment of outer space or wherever there is little or no atmospheric pressure. The commercial potential for this system is limited but the idea is offered due to its potential in those areas where its application might benefit an industrial user.
Technical Basics
The invention provides a pre-plasma cavity with two openings, one to accept an inert gas and a second allowing the plasma to exit; a structure to direct the plasma from the second opening to a welding cavity capable of being placed adjacent to a working surface and capable of accepting welding material. Means of regulating the flow rate of the inert gas is provided by use of needle or other precision valves, adjustable to vary the rate at which gas enters the pre-plasma chamber. Detailed information is contained in the patent number listed below. A copy is available at the address and telephone listed at the end of this document.
Potential Application(s)
The system provides for MIG welding in the environment of outer space or wherever there is little or no atmospheric pressure. The commercial potential for this system is limited but the idea is offered due to its potential in those areas where its application might benefit an industrial user.
Technology Commercialization Status
The patent for this technology has expired. Please reference case number MFS-28808-1 for additional information.
Related Technologies
Contact
If your company is interested in this technology please contact:
Sammy Nabors
NASA/Marshall Space Flight Center
Phone: (256) 544-5226
FAX: (256) 544-3151
E-mail: sammy.a.nabors@nasa.gov
Public Release Date: 10/5/2001
Reference Number: TOP8-45
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