Hot isostatic pressing process simulation: application to metal powders

2012 ◽  
Vol 90 (6) ◽  
pp. 573-583 ◽  
Author(s):  
L. Redouani ◽  
S. Boudrahem
Keyword(s):  
Experimental Data ◽  
Process Simulation ◽  
Hot Isostatic Pressing ◽  
Transport Mechanisms ◽  
Metal Powders ◽  
Isostatic Pressing ◽  
Powder Characteristics ◽  
Theoretical Results ◽  
Tungsten Powders ◽  
Good Agreement

Deformation and transport mechanisms of matter, which intervene in the powder densification process by hot isostatic pressing (HIP), are very complicated to put into equation form. Their contribution to densification depends on powder characteristics, their configuration in aggregates, and the used HIP cycle parameters (temperature, pressure, and time). In this work, we have envisaged modifications that seemed to us necessary to bring to the previous simulations, so that their predictions will be related to experiment. New equations were established to evaluate the efficient pressure and the contributions of different mechanisms. The obtained results are used for the construction of densification diagrams by the HIP of copper, nickel, and tungsten powders and to the comparison with the experimental data. The comparative tables, between theoretical results and experimental data, were established for tin and lead. The simulation predictions are in good agreement with experimental results.

Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Cold Compaction of Composite Powders

1999 ◽  
Vol 122 (1) ◽  
pp. 119-128 ◽  
Author(s):  
K. T. Kim ◽  
J. H. Cho ◽  
J. S. Kim
Keyword(s):  
Experimental Data ◽  
Tungsten Powder ◽  
Cold Isostatic Pressing ◽  
Metal Powders ◽  
Composite Powders ◽  
Cold Compaction ◽  
Isostatic Pressing ◽  
Proposed Model ◽  
Theoretical Predictions ◽  
Die Compaction

Densification behavior of composite powders was investigated under cold compaction. Experimental data were obtained for mixed copper and tungsten powders with various volume fractions of tungsten powder under cold isostatic pressing and die compaction. A model was also proposed for densification of mixed—soft and hard—metal powders under cold compaction. Theoretical predictions from the proposed model and models in the literature were compared with experimental data. The agreements between experimental data and theoretical predictions from the proposed model are very good for composite powders at initial stage under cold isostatic pressing. Theoretical predictions, however, underestimate experimental data under cold die compaction. [S0094-4289(00)01901-0]

In-Plane Vibrations of Thick Circular Rings With T or I Cross Sections

1979 ◽  
Vol 46 (2) ◽  
pp. 470-472
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Rings ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with the problem of eigenfrequencies and eigenvectors for rings whose cross section may be decomposed in basic rectangular cross sections. The solution is derived from a solution of the in-plane eigenvalue problem for rectangular cross-section thick rings. A good agreement between theoretical results and experimental data is obtained.

Analysis of Thermal Effects in Hydrodynamic Bearings

1986 ◽  
Vol 108 (2) ◽  
pp. 219-224 ◽  
Author(s):  
R. Boncompain ◽  
M. Fillon ◽  
J. Frene
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Effects ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Heat Transfer Equation ◽  
Reversed Flow ◽  
Theoretical Results ◽  
Generalized Reynolds Equation ◽  
Good Agreement

A general THD theory and a comparison between theoretical and experimental results are presented. The generalized Reynolds equation, the energy equation in the film, and the heat transfer equation in the bush and the shaft are solved simultaneously. The cavitation in the film, the lubricant recirculation, and the reversed flow at the inlet are taken into account. In addition, the thermoelastic deformations are also calculated in order to define the film thickness. Good agreement is found between experimental data and theoretical results which include thermoelastic displacements of both the shaft and the bush.

Thermal Behavior and Friction in Journal Bearings

1970 ◽  
Vol 92 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Al. Nica
Keyword(s):  
Experimental Data ◽  
Thermal Behavior ◽  
Heat Dissipation ◽  
Journal Bearings ◽  
Friction Torque ◽  
Operating Characteristics ◽  
Lubricant Flow ◽  
Theoretical Predictions ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with friction and the field of temperature in the lubricant film of journal bearings. Theoretical results regarding the thermal behavior are checked with experimental data and good agreement is found. Emphasis is put on the variation of temperature and lubricant flow with the operating characteristics of the bearing and it is seen that theoretical predictions for minima of friction torque are backed by temperature measurements. Further on, the friction torque and the mechanism of heat dissipation in bearings are dealt with, in order to verify the assumptions used in the calculation schemes. The means of efficiently cooling the bearing are also discussed, as well as the part played by the divergent zone in this process.

scholarly journals Added Mass and Damping of a Vibrating Rod in Confined Viscous Fluids

1976 ◽  
Vol 43 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. S. Chen ◽  
M. W. Wambsganss ◽  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Cylindrical Shell ◽  
Closed Form Solution ◽  
Added Mass ◽  
Form Solution ◽  
Viscous Fluids ◽  
Series Of Experiments ◽  
Theoretical Results ◽  
Good Agreement

This paper presents an analytical and experimental study of a cylindrical rod vibrating in a viscous fluid enclosed by a rigid, concentric cylindrical shell. A closed-form solution for the added mass and damping coefficient is obtained and a series of experiments with cantilevered rods vibrating in various viscous fluids is performed. Experimental data and theoretical results are in good agreement.

Sign in / Sign up

Export Citation Format

Share Document