Stress Analysis of Cold Die Compaction with Rotating Tools for Aluminum Powder

2007 ◽  
Vol 340-341 ◽  
pp. 1375-1380
Author(s):  
Y.H. Kim ◽  
Xiang Ma ◽  
H.C. Baek ◽  
Chang Hwy Lim
Keyword(s):  
Pressure Distribution ◽  
Aluminum Powder ◽  
Powder Compact ◽  
Applied Pressure ◽  
Simulation Software ◽  
Pressure Function ◽  
High Relative Density ◽  
Density Relationship ◽  
Die Compaction ◽  
Powder Compacts

In this paper, a modified slab analysis has been used to determine the pressure distribution in the cylindrical compaction of aluminum powder under rotating die compaction. The analytical results are discussed to explain the pressure distribution and the interaction of the various parameters. To predict the density distribution in a powder compact under an applied pressure with torsion, the pressure function is coupled with some form of a pressure density relationship. High relative density can be realized in powder compacts by the rotating die compaction in contrast to the conventional compaction. A numerical analysis, using the DEFORM3D simulation software, is also carried out on the compaction under the rotating punch.

scholarly journals Densification of Particulate Ceramic Composites: The Role of Heterogeneities

1989 ◽  
Vol 155 ◽  
Author(s):  
Lutgard C. De Jonghe ◽  
Mohamed N. Rahaman
Keyword(s):  
Composite Powder ◽  
Powder Compact ◽  
Ceramic Powder ◽  
Ceramic Composites ◽  
Negative Effects ◽  
Alternative Processing ◽  
Inclusion Phase ◽  
Die Compaction ◽  
Powder Compacts

ABSTRACTInert p articulate inclusions in ceramic powder compacts can obstruct densification behavior significantly. The factors that are the causes of this decrease in the sinterability are reviewed. It is concluded that the origin of the sintering difficulty resides in defects that processes such as die compaction introduce during the initial forming of the composite powder compact. Alternative processing methods are suggested that should minimize the negative effects of the dispersed inclusion phase on densification.

Characteristics of FeCuAl Powder Compacts Formed through Uniaxial Die Compaction Route

2017 ◽  
Vol 264 ◽  
pp. 103-106 ◽  
Author(s):  
M.M. Rahman ◽  
M.A. Ismail ◽  
H. Y. Rahman
Keyword(s):  
Electrical Resistivity ◽  
Relative Density ◽  
Bending Strength ◽  
Axial Loading ◽  
Homogeneous Distribution ◽  
Volumetric Expansion ◽  
Different Temperatures ◽  
Die Compaction ◽  
Powder Compacts ◽  
Interconnected Pores

This paper presents the development of FeCuAl powder compacts through uniaxial die compaction process. Iron powder ASC 100.29 was mechanically mixed with other elemental powders, i.e., copper (Cu), and aluminum (Al) for 30 minutes at a rotation of 30 rpm. The feedstock was subsequently shaped at three different temperatures, i.e., 30°C, 150°C, and 200°C through simultaneous upward and downward axial loading of 325 MPa. The as-pressed samples termed as green compacts were then sintered in argon gas fired furnace at 800°C for three different holding times, i.e., 30, 60, and 90 min at a rate of 10°C/min. The sintered samples were characterized for their relative density, electrical resistivity, and bending strength. The microstructure of the sintered samples was also evaluated through scanning electron microscopy (SEM). The results revealed that the sample formed at 150°C and sintered for 30 min obtained the best final characteristics, i.e., higher relative density, lower volumetric expansion and electrical resistivity, and higher bending strength. Microstructure evaluation also revealed that the sample formed at 150°C and sintered for 30 min obtained more homogeneous distribution of grains and less interconnected pores compared to the other samples.

Electro Discharge Compaction of WC-Co Composite Material Containing Particles of Diamond

2007 ◽  
Vol 534-536 ◽  
pp. 1181-1184 ◽  
Author(s):  
Evgeny Grigoriev ◽  
Alexander Rosliakov
Keyword(s):  
Composite Material ◽  
High Voltage ◽  
Electrical Discharge ◽  
Powder Compact ◽  
Applied Pressure ◽  
High Hardness ◽  
Maximum Level ◽  
Magnetic Pressure ◽  
Mechanical Pressure ◽  
Diamond Composite

In the present paper, the formation of high hardness and large strength structure of WCCo composite material containing particles of diamond were investigated and optimal operating parameters were defined. Tungsten carbide - cobalt - diamond composite was produced by the method of high voltage electrical discharge together with applying mechanical pressure to powder compact. It was found that the density and hardness of composite material reach its maximum values at certain magnitudes of applied pressure and high voltage electrical discharge parameters. We found that there is [a maximum level -Comment: Don’t you mean a maximum level?] for the discharge voltage and applied pressure beyond which the powder WC-Co-diamond composite material disintegrates like an exploding wire. Near this level, the cobalt particles are in a fused condition and are redistributed in the compact volume due to magnetic pressure of discharge current pulse. [The distribution of magnetic pressure is defined by the distribution of a current density in the powder compact. The magnetic pressure is more homogeneous in powder compact volume when the skin effect is strong.-Comment: Are these two statements of fact or conclusions made based on experimental observations? - Answer: The first statement is fact and the second statement is conclusion made based on experimental observations.]

scholarly journals Multi-resolution wavelet basis for solving steady forced Korteweg–de Vries model

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Somlak Utudee ◽  
Montri Maleewong
Keyword(s):  
Pressure Distribution ◽  
Flow Regime ◽  
Numerical Solutions ◽  
Mixed Boundary ◽  
Applied Pressure ◽  
Pressure Distributions ◽  
Multi Resolution Analysis ◽  
De Vries ◽  
Resolution Analysis ◽  
Critical Flow Regime

AbstractA steady forced Korteweg–de Vries (fKdV) model which includes gravity, capillary, and pressure distributions is solved numerically using the wavelet Galerkin method. The anti-derivatives of Daubechies wavelets are developed as the basis of the solution subspaces for the mixed boundary condition type. Accuracy of numerical solutions can be improved by increasing the number of wavelet levels in the multi-resolution analysis. The theoretical result of convergence rate is also shown. The problem can be viewed as gravity-capillary wave flows over an applied pressure distribution. The flow regime can be characterized by subcritical, supercritical, and critical flows depending on the value of the Froude number. Trapped depression and elevation waves are found over the pressure distribution. For a near-critical flow regime, a generalized solitary wave with ripples is presented. This shows a capillary effect in balance to gravity and the pressure force on the free surface.

A Useful Solution for Estimating Contact Pressure Between a Plate and Foundation

1999 ◽  
Vol 122 (4) ◽  
pp. 781-789
Author(s):  
L. B. Shulkin ◽  
D. A. Mendelsohn ◽  
G. L. Kinzel ◽  
T. Altan
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Finite Thickness ◽  
Applied Pressure ◽  
Three Dimensional ◽  
Sensitivity Study ◽  
Winkler Foundation ◽  
Contact Pressure Distribution ◽  
Design Variables

Many manufacturing situations involve a finite thickness plate or layer of material which is pressed against a much thicker foundation of the same or different material. One key example is a blank holder (plate) pressed against a die (foundation) in a sheet metal forming operation. In designing such a plate/foundation system the design objective often involves the contact stress distribution between the plate and foundation and the design variables are typically the thickness and modulus of the plate, the stiffness of the foundation and the applied pressure distribution on the noncontacting side of the plate. In general the problem relating the variables to the contact pressure distribution is three-dimensional and requires a complex finite element or boundary element solution. However, if the applied pressure distribution consists of sufficiently localized patches, which is often the case in applications, then an approximate 3D solution can be constructed by superposition. Specifically, the paper provides a convenient calculation procedure for the contact pressure due to a single circular patch of applied pressure on an infinite, isotropic, elastic layer which rests on a Winkler foundation. The procedure is validated by using known analytical solutions and the finite element method (FEM). Next a sensitivity study is presented for ascertaining the validity of the solution’s use in constructing solutions to practical problems involving multiple patches of loading. This is accomplished through a parametric study of the effects of loading radius, layer thickness, layer elastic properties, foundation stiffness and the form of the applied pressure distribution on the magnitude and extent of the contact pressure distribution. Finally, a procedure for determining an appropriate Winkler stiffness parameter for a foundation is presented. [S1087-1357(00)00603-1]

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