Morris, Timothy B. | Search NASA

NASA NTRS1994

Welding wire pressure sensor assembly

The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

Morris, Timothy B.↗

NASA NTRS1992

A prototype backside purge control system

New light-weight aluminum-lithium alloys are considered for propellant tank and aerospace structural applications. These alloys require more precise control of the welding atmosphere. Atmospheric oxygen contamination must be eliminated by flooding both the front and back sides of the weldment with an inert gas. This gas must be maintained at a desired pressure and flow rate that does not effect the stability of the weld process. The objective of the prototype backside purge control system being developed by Nichols Research Corporation (NRC) is to monitor and regulate the backside purge process and to develop a purge chamber design that enhances process controllability. This project will be conducted in two phases. The objective of Phase 1 is to develop a purge technique concept based on an investigation into the backside purge process. Phase 2 is to evaluate the backside purge concept developed in Phase 1.

Morris, Timothy B.↗