Microstructure and stability of melt spun INCONEL 713 LC
- PDF / 3,577,915 Bytes
- 8 Pages / 594 x 774 pts Page_size
- 22 Downloads / 232 Views
I.
INTRODUCTION
INTEREST in the field of rapid solidification rate (RSR) technology has been increasing over the past several years. Benefits envisioned include minimizing chemical segregation, elimination of massive phases, increases in the terminal solid solubility of alloying elements, production of otherwise metastable phases, and a reduction in grain size. The structural characteristics attained through rapid cooling, such as increased solubility and reduced grain size, will be thermodynamically metastable. Therefore, it is important to determine if the structures will be effectively stable in practical applications. In order to take full advantage of improved properties, the as-cast structure must be sufficiently stable to allow heat treatments and long-term use with no major microstructural changes. The desired properties include improved creep resistance for jet engine blades and vanes in the temperature range of 750 to 1100 ~ Techniques which are currently available for the production of RSR products include vapor deposition, ~ splat cooling, 2'3 centrifugal atomization, 4 and melt spinning. 5 In the area of melt spinning, a major effort has been directed toward examining the production and resulting microstructure of the as-solidified material. In this method, molten metal is forced under pressure onto a rapidly rotating wheel where solidification occurs, followed by separation of the material from the wheel in the form of thin metal ribbons. The interaction of processing parameters and the resulting as-cast structure has been well documented for many alloy systems in recent years. 5-8 For rapidly solidified materials to be widely used, further processing of the cast material is required. One possible processing method involves stacking the foils such that a strong alloy is used as the inner layer and an oxidation resistant material comprises the outer layers. Such a composite could be pressure-bonded by any *INCONEL is a trademark of the INCO family of companies. RANDY R. BOWMAN, Graduate Student, Fracture and Fatigue Research Laboratory, and STEPHEN D. ANTOLOVICH, Director, Fracture and Fatigue Research Laboratory and Professor and Head of Metallurgy, are with Georgia Institute of Technology, Atlanta, GA 30332 0100. This paper is based on a presentation made at the symposium "Physical Metallurgy of High Temperature Alloys" held at the fall meeting of the TMS-AIME in Philadelphia, PA on October 3 and 4, 1983 under the TMS-AIME High Temperature Alloys Committee. Manuscript submitted December 17, 1984. METALLURGICALTRANSACTIONS A
of a number of methods to form a sheet which is subsequently heat-treated, cut, and formed to shape. It is, therefore, necessary to understand not only the microstructure, but the stability of this structure as well in order to evaluate its reliability in actual applications. In this study the structure of melt spun IN 713-LC was examined by optical, scanning (SEM), and transmission electron microscopy (TEM) techniques. Characterization of the as-cast structure by electron diff
Data Loading...
