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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Two steel hemispheres are diffusion welded in an atmosphere of 0.00002 torr at a temperature of 2130 degrees F for 4 hours with a pressure of 4 psi holding the hemispheres together. Weld is accomplished with only microdeformation.
Weld quality monitor for production testing of welding strength in electronic circuitry
Stainless steel sheet-to-plate tee joint resistance welded by Magnetic Force Upset Welding process, testing performance
Liners for nitric and hydrofluoric acid tanks show no sign of deterioration after 18 months of continuous use. Each side of each edge of the polypropylene sheets is chamfered, and sheets are welded from both sides with polypropylene filler rod and a special hot-air welding torch.
Report proposes radiographic terminology standardization which allows scientific interpretation of radiographic films to replace dependence on individual judgement and experience. Report includes over 50 photographic pages where radiographs of aluminum welds with defects are compared with prepared weld sections photomacrographs.
Welding external aluminum jacket, tightly wrapped around inner layer of wood composition fiberboard, in oxygen free environment prevents combustion and subsequent damage to underlying fiberboard. Technique also applies to metal cutting in similar assemblies without disassembly to remove combustible materials from welding heat proximity.
Two-step solid state welding cycle applied to carefully prepared surfaces of an unrecrystallized alloy prevents loss of parent-metal strength at weld joint of dispersion-strengthened, nickel-chromium alloy.
Post weld annealing for stabilizing tungsten alloy weld structure
Welding thermal and residual stress analysis and material property and weld parameter effects on thermal stresses and elastoplastic deformation of aluminum alloys, steel, niobium, and tantalum
Weld quality monitor tests of Dumet/nickel ribbon welded joints
Development of optimum tungsten-inert-gas welding procedure for production of welds in 12 percent nickel maraging steel
Forge phase rigid and plastic region model of friction welding, deriving interfacial dispersion parameter of weld quality optimization
Introduction of sinusoidal signal across welded structure to determine reliability of integrated circuit connections is discussed. In-phase frequencies and quadrature frequency functions are used to evaluate weld reliability. Schematic diagram of test equipment and components is provided.
Objectives of study were: investigation of temperature changes caused by welding arc with analysis of temperature distribution; development of system of mathematical statements describing thermal stresses and plastic strains during welding; and development of system of mathematical solutions and computer programs for one-dimensional analysis.
Acoustic emission technique is described for use as quality control tool in nondestructive inspection of welds. Stress mounts around weld defect until it exceeds yield strength of material. Pressure wave relieving the stress is emitted and followed by oscillations caused by multiple reflections. Acoustic emissions are then detected by sensor similar to ultrasonic sensor.
Superior mechanical properties were obtained in metal joints weld-brazed between faying surfaces. Weld-braze applications and advantages are listed.
Welding technology is reviewed along with NASA's contributions to the technology. Specific examples of welding technology transfer are given.
A hardware and software specification covering requirements for the computer enhancement of structural weld radiographs was considered. Three scanning systems were used to digitize more than 15 weld radiographs. The performance of these systems was evaluated by determining modulation transfer functions and noise characteristics. Enhancement techniques were developed and applied to the digitized radiographs. The scanning parameters of spot size and spacing and film density were studied to optimize the information content of the digital representation of the image.