Search NASA⌕ Search

SEARCH · Search NASA

Results for “CAST”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Deburring die-castings by wet vibratory plant

A wet vibratory procedure for the removal of burrs from die castings is described. In this process synthetic abrasive chips and detergent solutions are agitated with the work in such a way as to produce a spiral circulatory movement. Details of various forms of vibrator basin and shapes of abrasive are illustrated. The automation of deburring is illustrated through the application of vibrators of spiral design in combination with transport and drying devices.

Loeschbart, H. M.↗
NASA NTRS1980

Analysis and calculation of macrosegregation in a casting ingot. MPS solidification model. Volume 1: Formulation and analysis

The physical and numerical formulation of a model for the horizontal solidification of a binary alloy is described. It can be applied in an ingot. The major purpose of the model is to calculate macrosegregation in a casting ingot which results from flow of interdendritic liquid during solidification. The flow, driven by solidification contractions and by gravity acting on density gradients in the interdendritic liquid, was modeled as flow through a porous medium. The symbols used are defined. The physical formulation of the problem leading to a set of equations which can be used to obtain: (1) the pressure field; (2) the velocity field: (3) mass flow and (4) solute flow in the solid plus liquid zone during solidification is presented. With these established, the model calculates macrosegregation after solidification is complete. The numerical techniques used to obtain solution on a computational grid are presented. Results, evaluation of the results, and recommendations for future development of the model are given. The macrosegregation and flow field predictions for tin-lead, aluminum-copper, and tin-bismuth alloys are included as well as comparisons of some of the predictions with published predictions or with empirical data.

Maples, A. L.↗
NASA NTRS1979

Development of high-cycle fatigue design curves for a cast aluminum alloy

Life prediction curves for rocket engine pump parts were developed from the results of high-cycle fatigue tests run on cast-aluminum specimens. Notched and smooth specimens were cyclically tested at different mean stress levels at -320 F (78 K). The notch size and mean stress enveloped the design operating conditions. Local stress computed in the groove of the notched specimen was used to represent its fatigue strength. The von Mises criterion was used to determine effective cyclic stresses. The Goodman rule was applied to determine equivalent reversed alternating stresses. The procedure permitted the notched and smooth data sets to each be described by a single curve. High-cycle fatigue life curves were provided for the stress state, mean stress, and stress concentration spanned by the data.

Cooper, R. A.↗
NASA NTRS1980

Development of exothermically cast single-crystal Mar-M 247 and derivative alloys

A low-cost, exothermic directional-solidification (DS) process was developed to produce single-crystal (SC) Mar-M 247 high-pressure turbine blades. Stress-rupture data indicated that SC Mar-M 247 provides only marginal improvements in longitudinal strength relative to the columnar grained DS material. Removal of grain boundary strengthening elements (B, C, Zr, Hf) from the Mar-M 247 composition (which are also melting point depressants) permitted the alloy to be solutioned at significantly higher temperatures. An order of magnitude improvement in rupture life relative to SC Mar-M 247 was observed for several derivative alloys at 103.5 MPa (15 KSI) and 1093 C. Rupture lives of the modified SC alloys were significantly affected by both alloy purity and heat treatment. Critical aspects of vacuum induction refining, exothermic casting technology, alloy development and heat treatment, which contributed to this new class of turbine blades, are reviewed

Strangman, T. E.↗
NASA NTRS1982

Low-Gravity Investigations in Cast-Iron Processing

Report on the state of the art in cast-iron processing identifies possible improvements that might result from processing in absence of gravity. Report suggests areas in which the knowledge of gravitational effects could eventually lead to practical improvements in material performance.

Frankhouser, W. L.↗
NASA NTRS1981

Creep and residual mechanical properties of cast superalloys and oxide dispersion strengthened alloys

Tensile, stress-rupture, creep, and residual tensile properties after creep testing were determined for two typical cast superalloys and four advanced oxide dispersion strengthened (ODS) alloys. The superalloys examined included the nickel-base alloy B-1900 and the cobalt-base alloy MAR-M509. The nickel-base ODS MA-757 (Ni-16CR-4Al-0.6Y2O3 and the iron-base ODS alloy MA-956 (Fe-20Cr-5Al-0.8Y2O3) were extensively studied, while limited testing was conducted on the ODS nickel-base alloys STCA (Ni-16Cr-4.5Al-2Y2O3) with a without Ta and YD-NiCrAl (Ni-16Cr-5Al-2Y2O3). Elevated temperature testing was conducted from 114 to 1477 K except for STCA and YD-NiCrAl alloys, which were only tested at 1366 K. The residual tensile properties of B-1900 and MAR-M509 are not reduced by prior creep testing (strains at least up to 1 percent), while the room temperature tensile properties of ODS nickel-base alloys can be reduced by small amounts of prior creep strain (less than 0.5 percent). The iron-base ODS alloy MA-956 does not appear to be susceptible to creep degradation at least up to strains of about 0.25 percent. However, MA-956 exhibits unusual creep behavior which apparently involves crack nucleation and growth.

Whittenberger, J. D.↗
NASA NTRS1981

Sputtered protective coatings for die casting dies

This investigation determined whether selected ion beam sputtered coatings on H-13 die steel would have the potential of improving the thermal fatigue behavior of the steel used as a die in aluminum die casting. The coatings were selected to test candidate insulators and metals capable of providing protection of the die surface. The studies indicate that 1 micrometer thick W and Pt coatings reduced the thermal fatigue more than any other coating tested and are candidates to be used on a die surface to increase die life.

Mirtich, M. J.↗
NASA NTRS1981

Silicon Ingot Casting - Heat Exchanger Method (HEM). Multi-Wire Slicing - Fixed Abrasive Slicing Technique (Fast). Phase 4 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-Cost Solar Array Project

The crystallinity of large HEM silicon ingots as a function of heat flow conditions is investigated. A balanced heat flow at the bottom of the ingot restricts spurious nucleation to the edge of the melted-back seed in contact with the crucible. Homogeneous resistivity distribution over all the ingot has been achieved. The positioning of diamonds electroplated on wirepacks used to slice silicon crystals is considered. The electroplating of diamonds on only the cutting edge is described and the improved slicing performance of these wires evaluated. An economic analysis of value added costs of HEM ingot casting and band saw sectioning indicates the projected add on cost of HEM is well below the 1986 allocation.

Schmid, F.↗
NASA NTRS1980

Thermal fatigue performance of integrally cast automotive turbine wheels

Fluidized bed thermal fatigue testing was conducted on 16 integrally cast automotive turbine wheels for 1000-10,000 (600 sec total) thermal cycles at 935/50 C. The 16 wheels consisted of 14 IN-792 + 1% Hf and 2 gatorized AF2-1DA wheels; 6 of the IN-792 + Hf wheels contained crack arrest pockets inside the blade root flange. Temperature transients during the thermal cycling were measured in three calibration tests using either 18 or 30 thermocouples per wheel. Thermal cracking based on crack length versus accumulated cycles was greatest for unpocketed wheels developing cracks in 8-13 cycles compared to 75-250 cycles for unpocketed wheels. However, pocketed wheels survived up to 10,000 cycles with crack lengths less than 20 mm, whereas two unpocketed wheels developed 45 mm long cracks in 1000-2000 cycles.

Humphreys, V. E.↗
NASA NTRS1981

Elevated temperature mechanical properties and residual tensile properties of two cast superalloys and several nickel-base oxide dispersion strengthened alloys

The elevated temperature tensile, stress-rupture and creep properties and residual tensile properties after creep straining have been determined for two cast superalloys and several wrought Ni-16Cr-4Al-yttria oxide dispersion strengthened (ODS) alloys. The creep behavior of the ODS alloys is similar to that of previously studied ODS nickel alloys. In general, the longitudinal direction is stronger than the long transverse direction, and creep is at least partially due to a diffusional creep mechanism as dispersoid-free zones were observed after creep-rupture testing. The tensile properties of the nickel-base superalloy B-1900 and cobalt-base superalloy MAR-M509 are not degraded by prior elevated temperature creep straining (at least up to 1 pct) between 1144 and 1366 K. On the other hand, the room temperature tensile properties of ODS nickel-base alloys can be reduced by prior creep strains of 0.5 pct or less between 1144 and 1477 K, with the long transverse direction being more susceptible to degradation than the longitudinal direction.

Whittenberger, J. D.↗
NASA NTRS1981

Hydrogen partitioning in pure cast aluminum as determined by dynamic evolution rate measurements

Hydrogen in pure aluminum can be found in two different states. One is related to a presence in gas-filled pores, while the other state involves the formation of a solid solution between hydrogen and aluminum. The considered investigation is concerned with the distribution of the hydrogen between various states. A dynamic technique is employed to measure the evolution of hydrogen from commercially available samples of polycrystalline pure aluminum under ultrahigh vacuum conditions. The obtained data are compared with the results of a statistical analysis concerning the porosity in the cast aluminum. It was found that more than 99 pct of the hydrogen in the aluminum is located in large pores. Less than 1 pct of the hydrogen is partitioned between the solid solution and the small pores.

Outlaw, R. A.↗
NASA NTRS1982

Effects of horizontal body casting on the baroreceptor reflex control of heart rate

The purpose of this study was to investigate the effects of long-term horizontal body position on baroreceptor reflex control of heart rate. Six male rhesus monkeys (6.2-9.4 kg) were given bolus injections of 4.0 microgram/kg, phenylephrine during each of the following conditions: awake, anesthetized (10 mg/kg ketamine HCl), and after beta-blockade (1 mg/kg propranolol HCl) before, 7, 14, and 28 days after being placed in a horizontal body cast. R-R interval vs. systolic arterial pressure was plotted, and the slope was determined by least-squares-fit linear regression. Baroreceptor slope was significantly reduced by 7 days of horizontal body position and remained attenuated throughout the 28-day restraint period both before and after beta-receptor blockade. These data are consistent with the thesis that prolonged exposure to a zero-gravity environment impairs autonomic reflex regulation of the cardiovascular system.

Billman, G. E.↗
NASA NTRS1982

Development of cast ferrous alloys for Stirling engine application

Low cost cast ferrous base alloys that can be used for cylinder and regenerator housing components of the Stirling engine were investigated. The alloys must meet the requirements of high strength and thermal fatigue resistance to approximately 1500 F, compatibility and low permeability with hydrogen, good elevated temperature oxidation/corrosion resistance, and contain a minimum of strategic elements. The phase constituents of over twenty alloy iterations were examined by X-ray diffraction. These alloy candidates were further screened for their tensile and stress rupture strength and surface stability in air at 1450 and 1600 F, respectively. Two alloys, NASAUT 1G (Fe-10Mn-20Cr-1.5C-1.0Si) and NASAUT 4G (Fe-15Mn-12Cr-3Mo-1.5C-1.0Si-1.0Nb), were chosen for more extensive elevated temperature testing. These alloys were found to exhibit nearly equivalent elevated temperature creep strength and oxidation resistance. Silicon present in these alloys at the 1 w/o level permitted the achievement of oxide scale adherence to 1600 F without loss of strength (or ductility) as was noted for equivalent additions of aluminum.

Lemkey, F. D.↗
NASA NTRS1980

Cast Fe-base cylinder/regenerator housing alloy

The development of an iron-base alloy that can meet the requirements of automotive Stirling engine cylinders and regenerator housings is described. Alloy requirements are as follows: a cast alloy, stress for 5000-hr rupture life of 200 MPa (29 ksi) at 775 C (1427 F), oxidation/corrosion resistance comparable to that of N-155, compatibility with hydrogen, and an alloy cost less than or equal to that of 19-9DL. The preliminary screening and evaluation of ten alloys are described.

Larson, F.↗
NASA NTRS1983

High Reynolds number tests of the CAST 10-2/DOA 2 airfoil in the Langley 0.3-meter transonic cryogenic tunnel, phase 1

A wind tunnel investigation of an advanced technology airfoil, the CAST 10-2/DOA 2, was conducted in the Langley 0.3 meter Transonic Cryogenic Tunnel (0.3 m TCT). This was the first of a series of tests conducted in a cooperative National Aeronautics and Space Administration (NASA) and the Deutsche Forschungs- und Versuchsanstalt fur Luft- und Raumfahrt e. V. (DFVLR) airfoil research program. Test temperature was varied from 280 K to 100 K to pressures from slightly above 1 to 5.8 atmospheres. Mach number was varied from 0.60 to 0.80, and the Reynolds number (based on airfoil chord) was varied from 4 x 10 to the 8th power to 45 x 10 to the 6th power. This report presents the experimental aerodynamic data obtained for the airfoil and includes descriptions of the airfoil model, the 0.3 m TCT, the test instrumentation, and the testing procedures.

Dress, D. A.↗