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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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Load and temperature effects on fatigue strength of notched titanium alloy sheet for supersonic transport operation
Outdoor high temperature corrosion tests for aluminum alloys and titanium alloys, and stainless steels
Salt stress corrosion cracking effects on tensile and stress rupture properties of titanium alloy sheet
Electrical, optical, magnetic and structural properties of titanium oxide, stressing transition difference with vanadium oxide
Temperature effects on mechanical properties and fracture behavior of lamellar Ni-nickel titanide intermetallic eutectic alloy showing dependence on intermetallic constituent
Notched specimens of titanium alloy and Inconel-718 exhibit little reduction of notch strength at certain low temperatures under 2000 lb/sq in. hydrogen, unnotched specimens are not embrittled at these temperatures. The degree of Inconel-718 embrittlement is lower than earlier observations under 1000 lb/sq in. hydrogen.
Tensile tests on titanium alloy, following abrasion under hydrogen and temperature cycling, reveal lowered tensile strength, increased ductility, and no embrittlement. Fretting the metal on itself in flowing hydrogen or abrading with an iron file in flowing hydrogen produces titanium hydride.
Stress corrosion tests of titanium alloys in fluids
Tensile properties of irradiated titanium, aluminum, and tin alloy at cryogenic temperature
Stress corrosion cracking behavior in titanium, molybdenum, and aluminum alloys, and electrochemical kinetic studies
Partial nucleotide sequences for fragments isolated from ribonuclease digests of tobacco mosaic virus RNA, suggesting genetic duplication possibility
Computer program calculates maximum potential flaw depth after specific cyclic pressure history. Kobayashi's solution to critical stress intensity equation and empirical relation for flaw growth rate are used. Program assesses pressure vessels of any material but only cylindrical or spherical shapes.
Calculation of lower critical fields and comparison with measured values for some niobium-titanium alloys
Electrochemistry of freshly generated titanium surfaces and stress corrosion cracking in aqueous solutions and in molten salts
Fatigue tests were conducted with constant-amplitude axial stresses in the ratio of minimum to maximum stress of 0.05 (R=0.05). Specimens with and without strain gages were tested at 21 C, and superalloy specimens with and without strain gages were tested at 21 C and 815 C.
Through- and surface-cracked specimens of two thicknesses were tested in uniaxial tension. Surface-cracked specimens were generally found to be stronger than through-cracked specimens with the same crack length. Apparent surface-crack fracture toughness calculated using the Anderson modified Irwin equation remained relatively constant for cracks as deep as 90 percent of the sheet thickness. Subcritical growth of surface cracks was investigated. Comparison of chamber and open air welds showed chamber welds to be slightly tougher. Both methods produced welds with toughness that compared favorably with that of the parent metal. Weld efficiencies were above 94 percent.
A method for fabricating titanium thermal protection system panels is described. The method has the potential for producing wide faying surface bonds to minimize temperature gradients and thermal stresses resulting during service at elevated temperatures. Results of nondestructive tests of the panels are presented. Concepts for improving the panel quality and for improved economy in production are discussed.
The spectra reported are important for the analysis of the spectra of CaXV and FeXXI. The extreme UV solar spectrum should contain some lines of these two ions. The spectroscopic source consisted of a low-inductance vacuum spark with electrodes made of the elements under investigation. Altogether 44 new lines in the region from 16 to 22 A were classified. Some previously unidentified lines of ClXII and ArXIII were also classified. The extrapolation of the ground-configuration energy levels is discussed.