Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “furnace”

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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Rapid melt/quench furnace using commercially available hardware

This report describes an off-the-shelf Orbital Tube Welder that can be easily used to melt and resolidify almost any electrically conductive material. This can be done on a KC-135 Aircraft within the microgravity period of one parabola. Melt sizes 3 mm diameter by 10 mm length and larger are feasible with most if not all materials. A highly reproducible, controlled, programmable heat and cool cycle can be provided. Sample measurements would have to be developed and could be as sophisticated or as simple as desired. These could include: optical and thermocouple temperature measurements, Peltier pulser for marking the solidification fronts, dimensional changes and whatever. Sample heat flows could be fixed over a very wide range being limited mostly by the cooling period, the desired sample size, and the 20 sec microgravity period of the KC-135 Aircraft parabola.

Poorman, Richard M.↗
NASA NTRS1987

Directional solidification in an imperfect furnace

The upward directional solidification of a binary alloy in which the rejected solute is more dense than the solvent is considered. The system is stably stratified both thermally and solutally. If heat is lost through the sidewalls, horizontal thermal gradients drive a steady double-diffusive convection. Solidification cells with small aspect ratios (width/length) A are considered, and asymptotic solutions to the steady double-diffusive system are obtained as A tends to 0 under the assumption heat losses are also small. When the thermal Grashof number is large, buoyancy boundary layers are at the sidewalls. The shape of the crystal-melt interface is determined by the coupled effects of local thermodynamic equilibrium, diffusion and convection.

Brattkus, K.↗
NASA NTRS1987

Multiple experiment processing furnace (MEPF) - An overview

A preliminary design has been developed for the MEPF capable of flying initially as a payload on the NASA/MSFC Materials Science Laboratory carrier in the Shuttle cargo bay and later on the Space Station as a rack-mounted payload in the pressurized volume of the U.S. Laboratory Module. The key requirements and the design approach are examined. It is noted that the MEPF modular design approach ensures maintainability and offers a reuse capability for up to 12 flights (with refurbishments and parts replacement between missions, if required). The design incorporates safety features, and adequate redundancy is built in to improve reliability of operations.

Srinivas, R.↗
NASA NTRS2019

High temperature electric arc furnace and method

An apparatus and process for improving the microstructure of electrically conducting materials is disclosed by the present invention. A revolving heat source applies heat to the surface of the material evenly and quickly. One or more heat sinks quickly cool the material. In the preferred embodiment, the cooling may be done in such a way as to promote as high a degree of directional grain growth as desired or completely nondirectional grain growth.

Richard M Poorman↗
NASA NTRS1993

Comparison of melt-solid interface position by radiography and temperature measurement in a vertical Bridgman furnace

The melt-solid interface position was measured during the Bridgman growth of germanium by both temperature profiling and by X-ray imaging. The temperature field of the ampoule, growth material and measurement thermocouples was analyzed by means of numerical analysis. It is shown that both the temperature shift and the discontinuity in temperature gradient is a function of the imposed thermal field and the thermal properties of the thermocouples.

Hubert, James A.↗
NASA NTRS1993

Thermal spray forming of refractory sample ampoule cartridges for single crystal growth space furnaces

A thermal spray process is being used to build up refractory metals and ceramics into a containment cartridge for high temperature, single crystal semiconductor growth experiments. This process uses high energy plasma inside a low pressure (100-200 torr) inert environment to apply layers of material onto a removable mandrel. A variety of materials are being characterized and evaluated against a demanding set of requirements, including high service temperature (1700 C), oxidation resistance, and resistance to liquid metal attack. Techniques to spray form refractory metals (tungsten, molybdenum, niobium, tantalum) and ceramics (alumina, boron nitride) are being developed in the Plasma Spray Cell at Marshall Space Flight Center. These plasma spray formed materials have been evaluated for mechanical properties, density, microstructure, and resistance to liquid metal attack. Forming techniques and the resultant mechanical and metallurgical properties will be presented.

Zimmerman, Frank↗
NASA NTRS1994

Furnace Tubes For Depositing Parylene-N(TM) On Hgl(2) Crystals

Shapes of quartz pyrolysis tubes used to deposit Parylene-N on Hgl(2) crystals modified to improve quality of coating. Use of zigzag tube, along with higher processing temperature, resulted in coating of better quality, including greater transparency and more uniformity of appearance. In addition, longer path taken by dimer in passing by baffles increases time spent in high-temperature region, increasing degree of cracking even more.

Iwanczyk, Jan S.↗
NASA NTRS1993

Thermal spray forming of refractory sample ampoule cartridges for single crystal growth space furnaces

A thermal spray process is being used to build up refractory metals and ceramics into a containment cartridge for high temperature, single crystal semiconductor growth experiments. This process uses high energy plasma inside a low pressure (100-200 torr) inert environment to apply layers of material onto a removable mandrel. A variety of materials are being characterized and evaluated against a demanding set of requirements, including high service temperature (1700 C), oxidation resistance, and resistance to liquid metal attack. Techniques to spray form refractory metals (tungsten, molybdenum, niobium, tantalum) and ceramics (alumina, boron nitride) are being developed in the Plasma Spray Cell at Marshall Space Flight Center. These plasma spray formed materials have been evaluated for mechanical properties, density, microstructure, and resistance to liquid metal attack. Forming techniques and the resultant mechanical and metallurgical properties are presented.

Zimmerman, Frank↗
NASA NTRS1993

The 1992-1993 advanced design program. Part 1: The Mars methane engine project. Part 2: The Mars oxygen processor new furnace

Three constituents of the Martian atmosphere, methane, carbon dioxide, and oxygen, can be used for internal combustion in engines utilized for future space exploration on Mars. These three gases, considered as the test case in this research, will be examined to determine required flow rates needed for combustion and optimization of engine performance. Results of the test case are examined in relation to a base case of methane and air for comparative purposes. Testing of exhaust temperatures, cylinder pressure, and exhaust gas analysis were performed for the base case and test case. Also described is a study utilizing a zirconia cell to convert carbon dioxide into usable oxygen to help support future Mars missions.

Lauer, Stephen↗
NASA NTRS1993

Crystal Growth Furnace (CGF)

The contract baseline, contract requirements review, contract modifications, contract problem areas and conclusions are addressed. Contract baseline was established 11 June 1987 and updated 1 December 1989. Significant changes were introduced into the 1989 baseline as compared to the original baseline. Contract modifications were made to add requirements as the program matured and as definition of requirements were completed. Problems were solved in real time through the contractor/customer team involvement and relationship to assure a timely and successful mission. The conclusion is that the CGF performed as designed and the experiments performed during the USML-1 Mission supports the conclusion.

Billingsley, Charles E.↗
NASA NTRS1996

Analysis of Residual Acceleration Effects on Transport and Segregation During Directional Solidification of Tin-Bismuth in the MEPHISTO Furnace Facility

The objective of this work is to approach the problem of determining the transport conditions (and effects of residual acceleration) during the plane-front directional solidification of a tin-bismuth alloy under low gravity conditions. The work involves using a combination of 2- and 3-D numerical models, scaling analyses, ID models and the results of ground-based and low-gravity experiments. The latter are to be conducted during the MEPHISTO experiment scheduled for USMP-3 in early 1996. The models will be used to predict the response of the transport conditions and consequent solute segregation in directionally solidifying tin-bismuth melt. Real-time Seebeck voltage variations across a Sn-Bi melt during directional solidification in MEPHISTO on USMP-1 show a distinct variation which can be correlated with thruster firings. The Seebeck voltage measurement is related to the response of the instantaneous average melt composition at the melt-solid interface. This allows a direct comparison of numerical simulations with the Seebeck signals obtained on USMP-1. The effects of such accelerations on composition for a directionally solidifying Sn-Bi alloy have been simulated numerically. USMP-1 acceleration data was used to assist in our choice of acceleration magnitude and orientation. The results show good agreement with experimental observations. The USMP-3 experiments took place earlier this year (February 22 through March 6). There were several differences between the USMP-3 experiments as compared to USMP-1. Firstly a more concentrated alloy was solidified and, secondly, Primary Reaction Control System thruster burns were requested at particular times during four separate growth runs. This allowed us to monitor the response Seebeck response under well-characterized growth conditions. In addition, we carried out simulations during the experiment in order to interpret the Seebeck signal. Preliminary results are described here.

Alexander J. Iwan D.↗
NASA NTRS1997

Magnetically Damped Furnace Bitter Magnet Coil 1

A magnet has been built by the National High Magnetic Field Laboratory for NASA on a cost reimbursement contract. The magnet is intended to demonstrate the technology and feasibility of building a magnet for space based crystal growth. A Bitter magnet (named after Francis Bitter, its inventor) was built consisting of four split coils electrically in series and hydraulically in parallel. The coils are housed in a steel vessel to reduce the fringe field and provide some on-axis field enhancement. The steel was nickel plated and Teflon coated to minimize interaction with the water cooling system. The magnet provides 0.14 T in a 184 mm bore with 3 kW of power.

Bird, M. D.↗