Materials Science in Space
- PDF / 489,036 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 100 Downloads / 255 Views
MATERIALS SCIENCE IN SPACE JOHN R. CARRUTHERS Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, California, USA* ABSTRACT The preparation of solid materials involves the control and manipulation of fluids in ways that are sensitive to gravitational influences. Although these effects are pervasive, surprisingly little is understood about phenomena such as natural convection and containerless processes under boundary conditions of interest to materials processing. Recent emphasis has focused on process fundamentals involving areas such as fluid dynamics, heat flow, and thermophysical property measurement as can be seen in this Symposium. Such a knowledge base is essential to any sensible evolution of the space environment as a capability for studying materials processing and preparing limited quantities of materials under quiescent or containerless conditions for subsequent assessment on earth. A brief overview of current work will be presented, together with possible future directions. INTRODUCTION The availability of the space environment to perform research on the processing of materials has represented a controversial and poorly understood opportunity to materials scientists, In large measure, perceptions about the utility of space for preparing materials under novel conditions have been based on the enthusiasm of visionaries and the self-interests of the aerospace community. Although these views represent an unmistakable, long-term direction for civilization, the basic knowledge from which such advances are derived must be well established first in materials science and technology. Perhaps one of the more revealing aspects of the use of space for preparing materials has been the relatively low level of sophistication attached to our current understanding of materials preparation processes. Recognition of the need to increase this understanding so as to achieve enhanced control over the structure, properties and performance of materials has been an increasingly important thrust in materials science and technology. The present interest in gravitational effects in fluids, from which most materials are ultimately prepared, has not only been stimulated by opportunities to regard gravity as a variable through space experiments; there has also been a long-standing interest in the ubiquitous effects of gravity on fluid behavior in materials processing configurations. The present Symposium provides a status review of the confluence of these separate interests which hopefully will demonstrate the nature of recent advances in our understanding of materials processing and the role of the space environment in contributing to our knowledge of these often complex processes. The strategy for use of the space environment to perform research on materials processing is similar to that for any other large, complex and expensive facility. One can look to facilities such as those which provide very high magnetic fields, very low or very high temperatures, a range of photon energies and intensities now available from accel
Data Loading...
