Constitutive Data for Powder Compaction Modeling

2000 ◽  
Vol 123 (2) ◽  
pp. 176-183 ◽  
Author(s):  
I. C. Sinka ◽  
A. C. F. Cocks ◽  
J. H. Tweed
Keyword(s):  
Constitutive Modeling ◽  
Triaxial Testing ◽  
Stress Space ◽  
Ceramic Powders ◽  
Compaction Behavior ◽  
Isostatic Compaction ◽  
Hard Metals ◽  
Testing Facility ◽  
Die Compaction ◽  
Radial Loading

The compaction behavior of steel powders, hard metals, and ceramic powders have been investigated using a newly developed high pressure triaxial testing facility. Results from isostatic compaction, simulated closed die compaction, and compaction along different radial loading paths in stress space are presented for six commercial powders. The experimental data are compared and considerations regarding the constitutive modeling of the compaction response of the different classes of materials are presented.

Persistence of Granular Structure during Die Compaction of Ceramic Powders

2000 ◽  
Vol 627 ◽  
Author(s):  
William J. Walker
Keyword(s):  
Low Pressure ◽  
Probability Of Failure ◽  
Model System ◽  
Granular Structure ◽  
Alumina Powder ◽  
Statistical Nature ◽  
Ceramic Powders ◽  
Glass Spheres ◽  
Die Compaction ◽  
Uniform Composition

ABSTRACTGlass spheres were used as a model system to investigate granule failure during die compaction. Stresses within an assembly of spheres follow a network of pathways. When the spheres are of uniform composition, the magnitude of the stresses within a pair of contacting granules is a function of the locally transmitted stress and the diameter of the two spheres. Results obtained using glass spheres demonstrated the statistical nature of granule failure during compaction, with some granules failing at very low applied pressures while others (∼40% by volume) persist at even the highest applied loads. Within a distribution of granule sizes, those granules with smaller diameter were seen to have a higher probability of failure at low pressure than were larger granules. These results are consistent with those observed during die compaction of granulated alumina powder.

Compaction Behavior of Several Ceramic Powders

1962 ◽  
Vol 45 (3) ◽  
pp. 97-101 ◽  
Author(s):  
A. R. COOPER ◽  
L. E. EATON
Keyword(s):  
Ceramic Powders ◽  
Compaction Behavior

Micro Fabrication Process of Powder Compact with Semi-Solid Mold

2007 ◽  
Vol 534-536 ◽  
pp. 473-476
Author(s):  
Fujio Tsumori
Keyword(s):  
Melting Point ◽  
Powder Compact ◽  
Control Process ◽  
Compaction Process ◽  
Micro Fabrication ◽  
Isostatic Compaction ◽  
Micro Parts ◽  
Die Compaction ◽  
Semi Solid ◽  
Micro Cavity

New powder compaction process, in which a Bingham semi-solid/fluid mold is utilized, is developed to fabricate micro parts. In the present process, a powder material is filled as slurry in a solid wax mold, dried and compressed by either of conventional pressing methods, such as isostatic pressing or die compaction. It is important to use slurry for filling because dry powder is hard to fill in the micro cavity. It is also essential to control process temperature to treat micro parts. The wax mold is heated during compaction and becomes semi-solid state, which can acts as a pressurized medium for isostatic compaction. Since the compacted micro parts are very fragile, the mold's temperature is controlled to higher than its melting point during unloading, to avoid breakage of the compacts. To demonstrate effectiveness of this process, some micro compacts of alumina are shown as examples.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

Sign in / Sign up

Export Citation Format

Share Document