Skip to main content

Currently Skimming:

3 Ability of the Space Station Furnace Facility Core to Support Materials Science Experiments that Require a Microgravity Environment
Pages 29-46

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 29...
... The chapter ends with the committee's overarching conclusions anct recommendations about the current SSFF Core concept. The committee's evaluations of the applicability of the current SSFF Core concept to the neects of the metals anct alloys research area anct the electronic anct photonics (semiconcluctor)
From page 30...
... R Trivedi Iowa State University Coupled Growth in Hypermonotectics Al-Mn Particle Engulfment and A1 and Al-Ni Pushing by Solidifying + SiC and Interfaces zirconia particles Diffusion Processes in Molten Semiconductors Fundamental Aspects of Vapor Deposition and Etching under Diffusion Controlled Transport Conditions Investigation of the Relationship between Undercooling and and Solidification Velocity Equiaxed Dendritic Solidification Experiment Physical Properties and Processing of Undercooled Metallic Glass Forming Liquids Orbital Processing of Eutectic Rod-Like Arrays Space-Based and Ground-Based Crystal Growth Using Magnetically Coupled Baffle Comparison of Structure and Segregation in Alloys Directionally Solidified in Terrestrial and Microgravity Environments Self-Diffusion in Liquid Elements Crystal Growth of ZnSe and Related Ternary Compound Semiconductors by Vapor Transport Interface Pattern Selection Criterion for Cellular Structures in Directional Solidification Ge:Ga Ge:Sb Ge:(Si,Ga)
From page 31...
... shows that the subdiscipline of metals anct alloys currently constitutes a substantial portion of the entire MRD materials-science research program. The importance of metals anct alloys in NASA-sponsorect microgravity research was recognized in the National Research Council report, Microgravity Research Opportunitiesfor the 1990s: "The microgravity environment, by reducing .
From page 32...
... A technologically important example of a eutectic alloy with an alignect microstructure is manganese-bismuth, which has an extraorctinarily high magnetic coercivity that approaches the theoretical limit (Pirich anct Larson, 19821. The size anct spacing of the magnetic phase in material solictifiect on earth with a strong convective flow agree with theory, whereas a pronounced discrepancy is found in samples solictifiect in a microgravity environment.
From page 33...
... However, buoyancyctriven sedimentation should be largely eliminated in a microgravity environment. So far, microgravity experiments have been only partially successful in producing uniform dispersions (Lacy anct Otto, 1975)
From page 34...
... Ability of Space Station Furnace Facility Core to Support Microgravity Metallurgical Research The current SSFF Core concept is particularly useful for high-temperature metals anct alloys research. However, the concept cloes not support studies on Tow-temperature metals anct alloys, which are not only scientifically and technologically important but can also serve as moclels for high-temperature materials, thus reducing the cost anct time of experimenting at high temperatures.
From page 35...
... Unfortunately, previous studies of semiconductor growth in space have only occasionally achieved the two goals specified above. The section on crystal growth and defect generation control in the December 4, 1996, NRA clearly shows that the elimination of Buid flow in the microgravity environment is complicated by surface-tension-driven convective Row and density-driven flows that might actually be suppressed at one g but are enhanced by g-jitter and by residual low g in directions not normally encountered in terrestrial growth.
From page 36...
... It is not obvious in either of these latter studies how studying the growth parameters will provide insights into the funciamentals of how anct why clefects are formect. Ability of Space Station Furnace Facility Core to Supper!
From page 37...
... Three of the five candidate experiments should be able to take advantage of the current SSFF Core concept. One, or possibly two, require or might benefit from the use of magnetic suppression of residual convection.
From page 38...
... The melt processing anct diffusion studies require elevatect temperatures, anct one also requires levitation. Of the eight grounctbasect programs that are currently being concluctect, three concern solution processing, one concerns mocleling, four concern processing or investigation of oxide melts, anct one concerns both oxide melts and metallic glasses.
From page 39...
... In many of these experiments, microgravity would elucidate mechanisms. It is possible that future ceramics research might benefit substantially from microgravity research, so it is incumbent upon NASA to provide as fully as possible for ceramics research in the current SSFF Core concept.
From page 40...
... Many ceramic experiments are performed at temperatures between ambient ancl 500C, a regime for which the current SSFF Core is not clesignect. To make the current SSFF Core concept more generally useful for ceramics, the temperature capability wouicl have to be extended by the installation of cooling circuits ancl control strategies that wouicl permit temperature ramps ancl temperature control in
From page 41...
... make it important to consider changes to the current Core concept to accommodate more ceramic and glass experiments. POLYMERIC MATERIALS None of the 13 research projects selected by NASA as candidate investigations for the ISS (Table 3-1)
From page 42...
... Polymer microfabrication is another area in which structure is affected by mechanical or interface ctirectect deformations, effects that might be subject to manipulation in microgravity. Ability of Space Station Furnace Facility Core to Support Polymer Research A major concern in microgravity polymer research is how well the current SSFF Core design will be able to contribute to establishing a broacler program in this area.
From page 43...
... All equipment in the current SSFF Core concept should be re-examinect in terms of its applicability to the broadest range of materials research areas anct experiments. NASA should consider redesigning the current SSFF Core concept in the following ways to facilitate microgravity materials-science
From page 44...
... Capabilities The temperature-control hardware in the current SSFF Core concept is clesignect to maintain anct program temperature conditions between 500C anct 2300C. For certain types of experiments in all of the materials research areas, however, it will be important to control temperatures and program conditions well below 500C (i.e., at temperatures of 25C to 500C)
From page 45...
... NASA should consider acicting liquict-mixing and liquict-Bow control capabilities to the current SSFF Core concept to support materials research that involves a liquid state.
From page 46...
... 46 Fly MA SERIALS SCIENCE RESEARCH ON THE INTERNS TIONAl SPA CE SEA TION Power Availability Consiclerable power will be required to produce the high temperatures, levitation, and magnetic clamping required for many of the experiments currently planned for the SSFF Core. Careful planning will be required to ensure that sufficient power can be cleliverect to each unit.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.