Tantalum powder consolidation, modeling and properties

Technical Report · Tue Oct 01 04:00:00 EDT 1996

DOI:https://doi.org/10.2172/383641· OSTI ID:383641

Bingert, S R; Vargas, V D; Sheinberg, H C

A systematic approach was taken to investigate the consolidation of tantalum powders. The effects of sinter time, temperature and ramp rate; hot isostatic pressing (HIP) temperature and time; and powder oxygen content on consolidation density, kinetics, microstructure, crystallographic texture, and mechanical properties have been evaluated. In general, higher temperatures and longer hold times resulted in higher density compacts with larger grain sizes for both sintering and HIP`ing. HIP`ed compacts were consistently higher in density than sintered products. The higher oxygen content powders resulted in finer grained, higher density HIP`ed products than the low oxygen powders. Texture analysis showed that the isostatically processed powder products demonstrated a near random texture. This resulted in isotropic properties in the final product. Mechanical testing results showed that the HIP`ed powder products had consistently higher flow stresses than conventionally produced plates, and the sintered compacts were comparable to the plate material. A micromechanics model (Ashby HIP model) has been employed to predict the mechanisms active in the consolidation processes of cold isostatic pressing (CIP), HIP and sintering. This model also predicts the density of the end product and whether grain growth should be expected under the applied processing conditions.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 383641
• Report Number(s): LA-UR--96-2423; CONF-960202--34; ON: DE96014237
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COLD PRESSING
COMPACTING
EXPERIMENTAL DATA
HOT PRESSING
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MICROSTRUCTURE
POWDER METALLURGY
SINTERING
TANTALUM
TEMPERATURE DEPENDENCE
TEXTURE
TIME DEPENDENCE