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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

High temperature, low-cycle fatigue of copper-base alloys in argon. Part 1: Preliminary results for 12 alloys at 1000 F (538 C)

Short-term tensile evaluations at room temperature and 538 C and low-cycle fatigue evaluations at 538 C are presented for the following materials: Zirconium copper-annealed, Zirconium copper-1/4 hard, Zirconium copper-1/2 hard, Tellurium copper-1/2 hard, Chromium copper-SA and aged, OFHC copper-hard, OFHC copper-1/4 hard, OFHC copper-annealed, Silver-as drawn, Zr-Cr-Mg copper-SA, CW and aged, Electroformed copper-30-35 ksi, and Co-Be-Zr- copper-SA, aged. A total of 50 tensile tests and 76 low-cycle fatigue tests were performed using a strain rate of 0.2 percent per second.

Conway, J. B.↗
NASA NTRS1982

Diamond Sheet: A new diamond tool material

Diamond sheet is termed a diamond tool material because it is not a cutting tool, but rather a new material from which a variety of different tools may be fabricated. In appearance and properties, it resembles a sheet of copper alloy with diamond abrasive dispersed throughout it. It is capable of being cut, formed, and joined by conventional methods, and subsequently used for cutting as a metal bonded diamond tool. Diamond sheet is normally made with industrial diamond as the abrasive material. The metal matrix in diamond sheet is a medium hard copper alloy which has performed well in most applications. This alloy has the capability of being made harder or softer if specific cutting conditions require it. Other alloys have also been used including a precipitation hardened aluminum alloy with very free cutting characteristics. The material is suitable for use in a variety of cutting, surfacing, and ring type tools, as well as in such mundane items as files and sandpaper. It can also be used as a bearing surface (diamond to diamond) and in wear resistant surfaces.

Mackey, C. R.↗
NASA NTRS1977

Graphical method for predicting life of a rocket thrust chamber with half-hard zirconium-copper liner and electroformed nickel closeout

A method for estimating the life of a regeneratively cooled rocket thrust chamber was developed and is based on the hot-gas wall temperature and the temperature difference between the hot-gas wall and the outside surface of the closeout. This method permits a quick estimate of the life of a thrust chamber when design changes or test-cycle variations are considered. Strain range and life are presented graphically as functions of these temperature parameters for a typical high-performance rocket thrust chamber with a half-hard zirconium-copper liner and an electroformed nickel closeout.

Kasper, H. J.↗
NASA NTRS1930

The relation between the tensile strength and the hardness of metals

This report presents methods determining the hardness and tensile strength of metals by showing the effect and dependence of the hardness numbers on the strain-hardening. Relations between the hardness numbers and the ordinary stress-strain diagrams and tensile strength are given. Procedures for finding the Brinell strength are also presented.

METALS - NICKEL HARDNESS TESTS↗
NASA NTRS1976

High temperature, low-cycle fatigue of copper-base alloys for rocket nozzles. Part 2: Strainrange partitioning and low-cycle fatigue results at 538 deg C

Low-cycle fatigue tests of 1/2 Hard AMZIRC Copper and NARloy Z were performed in argon at 538 C to determine partitioned strain range versus life relationships. Strain-controlled low-cycle fatigue tests of a Zr-Cr-Mg copper-base alloy were also performed. Strain ranges, lower than those employed in previous tests, were imposed in order to extend the fatigue life curve out to approximately 400,000 cycles. An experimental copper alloy and an experimental silver alloy were also studied. Tensile tests were performed in air at room temperature and in argon at 538 C. Strain-controlled low-cycle fatigue tests were performed at 538 C in argon to define the fatigue life over the regime from 300 to 3,000 cycles. For the silver alloy, three additional heat treatments were introduced, and a limited evaluation of the short-term tensile and low-cycle fatigue behavior at 538 C was performed.

Conway, J. B.↗
NASA NTRS1973

High temperature, low-cycle fatigue of copper-base alloys in argon. Part 2: Zirconium-copper at 482, 538 and 593 C

Zirconium-copper (1/2 hard) was tested in argon over the temperature range from 482 to 593 C in an evaluation of short-term tensile and low-cycle fatigue behavior. The effect of strain rate on the tensile properties was evaluated at 538 C and in general it was found that the yield and ultimate strengths increased as the strain rate was increased from 0.0004 to 0.01/sec. Ductility was essentially insensitive to strain rate in the case of the zirconium-copper alloy. Strain-rate and hold-time effects on the low cycle fatigue behavior of zirconium-copper were evaluated in argon at 538 C. These effects were as expected in that decreased fatigue life was noted as the strain rate decreased and when hold times were introduced into the tension portion of the strain-cycle. Hold times in compression were much less detrimental than hold times in tension.

Conway, J. B.↗
NASA NTRS1973

High temperature, low cycle fatigue of copper-base alloys in argon. Part 3: Zirconium-copper; thermal-mechanical strain cycling, hold-time and notch fatigue results

The low-cycle fatigue characteristics of smooth bar and notched bar specimens (hourglass shape) of zirconium-copper, 1/2 Hard, material (R-2 Series) were evaluated at room temperature in axial strain control. Over the fatigue life range from about 300 to 3000 cycles the ratio of fatigue life for smooth bar to fatigue life for notched bar remained constant at a value of about 6.0. Some additional hold-time data for the R-2 alloy tested in argon at 538 C are reported. An analysis of the relaxation data obtained in these hold-time tests is also reported and it is shown that these data yield a fairly consistent correlation in terms of instantaneous stress rate divided by instantaneous stress. Two thermal-mechanical strain cycling tests were also performed using a cyclic frequency of 4.5 cycles per hour and a temperature cycling interval from 260 to 538 C. The fatigue life values in these tests were noticeably lower than that observed in isothermal tests at 538 C.

Conway, J. B.↗
NASA NTRS1975

Ultrasonically bonded value assembly

A valve apparatus capable of maintaining a fluid-tight seal over a relatively long period of time by releasably bonding a valve member to its seat is described. The valve member is bonded or welded to the seat and then released by the application of the same energy to the bond joint. The valve member is held in place during the bonding by a clamping device. An appropriate force device can activate the opening and closing of the valve member. Various combinations of material for the valve member and valve seat can be utilized to provide an adequate sealing bond. Aluminum oxide, stainless steel, inconel, tungsten carbide as hard materials and copper, aluminum, titanium, silver, and gold as soft materials are suggested.

Salvinski, R. J.↗
NASA NTRS2015

Body of Knowledge (BOK) for Copper Wire Bonds

Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications. An evaluation of copper wire bond technology for applicability to spaceflight hardware may be warranted along with concurrently compiling a comprehensive understanding of the failure mechanisms involved with copper wire bonded semiconductor devices.

Body of Knowledge (BOK)↗
NASA NTRS1971

Bipropellant shut-off valve

An advanced design of an all metal, fast response, bipropellant, shut-off valve for use on long duration space missions is reported. The valve provides the flow control capability for a 1,000 lb thrust, bipropellant engine using oxygen difluoride and diborane as propellants. The shutoff seal selection is a soft-on-hard metal concept. The soft seal is a spherical shell that seats against a hard conical seat. Beryllium copper and beryllium nickel seals were selected to seal against an electrolyzed Inconel 718 seat. Poppet shaft sealing is achieved by use of hydroformed, Inconel 718 bellows. Two valve assemblies were fabricated and subjected to a series of tests including leak, response time, flow capacity, dry cycles, water cycles, liquid nitrogen cycles, liquid fluorine cycles, and lead-lag operation cycles. These tests demonstrated the ability of the valve to meet design goals.

Smith, J. V.↗
NASA NTRS1993

Application of hard coatings to substrates at low temperatures

BIRL, the industrial research laboratory of Northwestern University, has conducted unique and innovative research, under sponsorship from the NASA Marshall Space Flight Center (MSFC), in the application of hard, wear resistant coatings to bearing steels using the high-rate reactive sputtering (HRRS) process that was pioneered by Dr. William Sproul, the principal investigator on this program. Prior to this program, Dr. Sproul had demonstrated that it is possible to apply hard coatings such as titanium nitride (TiN) to alloy steels at low temperatures via the HRRS process without changing the metallurgical properties of the steel. The NASA MSFC program at BIRL had the specific objectives to: apply TiN to 440C stainless steel without changing the metallurgical properties of the steel; prepare rolling contact fatigue (RCF) test samples coated with binary hard coatings of TiN, zirconium nitride (ZrN), hafnium nitride (HfN), chromium nitride (CrN), and molybdenum nitride (MoN), and metal coatings of copper (Cu) and gold (Au); and develop new alloyed hard coatings of titanium aluminum nitride (Ti(0.5)Al(0.5)N), titanium zirconium nitride (Ti(0.5)Zr(0.5)N), and titanium aluminum vanadium nitride.

Sproul, William D.↗
NASA NTRS1993

Nucleation of the diamond phase in aluminium-solid solutions

Precipitation was studied from fcc solid solutions with silicon, germanium, copper and magnesium. Of all these elements only silicon and germanium form diamond cubic (DC) precipitates in fcc Al. Nucleation of the DC structure is enhanced if both types of atom are dissolved in the fcc lattice. This is interpreted as due to atomic size effects in the prenucleation stage. There are two modes of interference of fourth elements with nucleation of the DC phase in Al + Si, Ge. The formation of the DC phase is hardly affected if the atoms (for example, copper) are rejected from the (Si, Ge)-rich clusters. If additional types of atom are attracted by silicon and/or germanium, DC nuclei are replaced by intermetallic compounds (for example Mg2Si).

Hornbogen, E.↗
NASA NTRS1992

X ray based displacement measurement for hostile environments

A new method on noncontacting, high temperature extensometry based on the focus and scanning of x rays is currently under development and shows great promise of overcoming limitations associated with available techniques. The chief advantage is the ability to make undisturbed measurements through stratified or flowing gases, smoke, and flame. The system is based on the ability to focus and scan low energy, hard x rays such as those emanating from copper or molybdenum sources. The x rays are focused into a narrow and intense line image which can be scanned onto targets that fluoresce secondary x ray radiation. The final goal of the system is the ability to conduct macroscopic strain measurements in hostile environments by utilizing two or more fluorescing targets. Current work is limited to displacement measurement of a single target with a resolution of 1.25 micro-m and a target temperature of 1200 C, directly through an open flame. The main advantage of the technique lies in the penetrating nature of x rays which are not affected by the presence of refracting gas layers, smoke, flame, or intense thermal radiation, all of which could render conventional extensometry methods inoperative or greatly compromise their performance.

Canistraro, Howard A.↗
NASA NTRS2013

Compact Focal Plane Assembly for Planetary Science

A compact radiometric focal plane assembly (FPA) has been designed in which the filters are individually co-registered over compact thermopile pixels. This allows for construction of an ultralightweight and compact radiometric instrument. The FPA also incorporates micromachined baffles in order to mitigate crosstalk and low-pass filter windows in order to eliminate high-frequency radiation. Compact metal mesh bandpass filters were fabricated for the far infrared (FIR) spectral range (17 to 100 microns), a game-changing technology for future planetary FIR instruments. This fabrication approach allows the dimensions of individual metal mesh filters to be tailored with better than 10- micron precision. In contrast, conventional compact filters employed in recent missions and in near-term instruments consist of large filter sheets manually cut into much smaller pieces, which is a much less precise and much more labor-intensive, expensive, and difficult process. Filter performance was validated by integrating them with thermopile arrays. Demonstration of the FPA will require the integration of two technologies. The first technology is compact, lightweight, robust against cryogenic thermal cycling, and radiation-hard micromachined bandpass filters. They consist of a copper mesh supported on a deep reactive ion-etched silicon frame. This design architecture is advantageous when constructing a lightweight and compact instrument because (1) the frame acts like a jig and facilitates filter integration with the FPA, (2) the frame can be designed so as to maximize the FPA field of view, (3) the frame can be simultaneously used as a baffle for mitigating crosstalk, and (4) micron-scale alignment features can be patterned so as to permit high-precision filter stacking and, consequently, increase the filter bandwidth and sharpen the out-of-band rolloff. The second technology consists of leveraging, from another project, compact and lightweight Bi0.87Sb0.13/Sb arrayed thermopiles. These detectors consist of 30-layer thermopiles deposited in series upon a silicon nitride membrane. At 300 K, the thermopile arrays are highly linear over many orders of magnitude of incident IR power, and have a reported specific detectivity that exceeds the requirements imposed on future mission concepts. The bandpass filter array board is integrated with a thermopile array board by mounting both boards on a machined aluminum jig.

Brown, Ari↗
NASA NTRS1992

X-ray-based displacement measurement for hostile environments

A new method on noncontacting, high temperature extensometry based on the focus and scanning of X-rays is currently under development and shows great promise of overcoming limitations associated with available techniques. The chief advantage is the ability to make undisturbed measurements through stratified or flowing gases, smoke, and flame. The system is based on the ability to focus and scan low energy, hard X-rays such as those emanating from copper or molybdenum sources. The X-rays are focused into a narrow and intense line image which can be scanned onto targets that fluoresce secondary X-ray radiation. The final goal of the system is the ability to conduct macroscopic strain measurements in hostile environments by utilizing two or more fluorescing targets. Current work is limited to displacement measurement of a single target with a resolution of 1.25 micro-m and a target temperature of 1200 C, directly through an open flame. The main advantage of the technique lies in the penetrating nature of X-rays which are not affected by the presence of refracting gas layers, smoke, flame, or intense thermal radiation, all of which could render conventional extensometry methods inoperative or greatly compromise their performance.

Canistraro, H. A.↗
NASA NTRS1994

Tropospheric HO determination by FAGE

In the measurement of tropospheric HO we have employed three low-pressure laser-excited fluorescence (LEF) experimental systems. These instruments operate by expanding the ambient air flow via a nozzle, followed by transit down a flowtube through a detection region traversed by the excitation laser beam. This sampling method we named FAGE (fluorescence assay with gas expansion). The instruments employed a hydrocarbon reagent, added below the nozzle, to remove HO for background measurement. In the second and third instruments, air sampling via parallel nozzles and tubes, with reagent addition alternating between two channels, permitted continuous signal measurement with simultaneous measurement of background. The first two instruments (FAGE1 and FAGE2) used 282 nm HO excitation by frequency-doubled tunable dye lasers, pumped by pulsed Nd:YAG lasers at 10-30 Hz repetition rate. The third instrument (FAGE3) uses 308 nm excitation in which the dye laser is pumped by a copper vapor laser, pulsed at 5600 Hz.

Hard, Thomas M.↗