scholarly journals A Precaution on Using 316L Stainless Wire in Hgms Matrices

1986 ◽  
Vol 2 (2) ◽  
pp. 91-94
Author(s):  
Marshall D. Graham
Keyword(s):  
Matrix Material ◽  
Filtration Efficiency ◽  
Austenitic Alloys ◽  
Magnetic Filtration ◽  
Magnetizing Field

Use of unannealed 316L stainless wire as HGMS matrix material in an application requiring frequent reversals of the magnetizing field has been noted to result in slow degradation of matrix magnetization characteristics, with attendant reductions in magnetic filtration efficiency. This alloy should be restricted to applications where field reversals are seldom required, particularly if it is exposed to corroding fluids. A similar precaution probably applies to other austenitic alloys.

Effect of Chemical State of Dispersed Phase on Magnetic Filtration Efficiency

2004 ◽  
Vol 39 (12) ◽  
pp. 2827-2838 ◽  
Author(s):  
Soichi Sato ◽  
Kazunari Mitsuhashi ◽  
Takeshi Ohara
Keyword(s):  
Filtration Efficiency ◽  
Chemical State ◽  
Dispersed Phase ◽  
Magnetic Filtration

scholarly journals THE EFFECT OF THE COEFFICIENT OF RESTITUTION TO THE PARTICLE COLLECTION EFFICIENCY DURING THE PROCESS OF MAGNETIC FILTRATION - NUMERICAL APPROACH

2015 ◽  
Vol 9 (1) ◽  
pp. 38-44
Author(s):  
Giorgos Kouropoulos
Keyword(s):  
Collection Efficiency ◽  
Numerical Approach ◽  
Elastic Collision ◽  
Coefficient Of Restitution ◽  
Filtration Efficiency ◽  
Particle Collection ◽  
Magnetic Filter ◽  
Magnetic Filtration ◽  
Physical Quantities

In the present study, the effect of the coefficient of restitution to the particle collection efficiency of magnetic filter during magnetic filtration of a fluid will be examined. Initially, are described the available mathematical models that give efficiency of magnetic filtration in relation to various parameters and physical quantities. Also, the role of coefficient of restitution in the magnetic filtration models will be reported. Furthermore, is formulated the basic equation that examines the change of filtration efficiency with regard to the coefficient of restitution. In the last step, a numerical example with given values from a real magnetic filter will be applied and the characteristic curves of magnetic filter will be drawn. The general conclusion that we have is that as the coefficient of restitution increases, the efficiency of magnetic filter decreases. The efficiency of magnetic filter converges in the same value, when there is elastic collision of a filtered particle.

scholarly journals THE EFFECT OF THE COEFFICIENT OF RESTITUTION TO THE PARTICLE COLLECTION EFFICIENCY DURING THE PROCESS OF MAGNETIC FILTRATION - NUMERICAL APPROACH

2015 ◽  
Vol 9 (1) ◽  
pp. 38-44
Author(s):  
Giorgos Kouropoulos
Keyword(s):  
Collection Efficiency ◽  
Numerical Approach ◽  
Elastic Collision ◽  
Coefficient Of Restitution ◽  
Filtration Efficiency ◽  
Particle Collection ◽  
Magnetic Filter ◽  
Magnetic Filtration ◽  
Physical Quantities

In the present study, the effect of the coefficient of restitution to the particle collection efficiency of magnetic filter during magnetic filtration of a fluid will be examined. Initially, are described the available mathematical models that give efficiency of magnetic filtration in relation to various parameters and physical quantities. Also, the role of coefficient of restitution in the magnetic filtration models will be reported. Furthermore, is formulated the basic equation that examines the change of filtration efficiency with regard to the coefficient of restitution. In the last step, a numerical example with given values from a real magnetic filter will be applied and the characteristic curves of magnetic filter will be drawn. The general conclusion that we have is that as the coefficient of restitution increases, the efficiency of magnetic filter decreases. The efficiency of magnetic filter converges in the same value, when there is elastic collision of a filtered particle.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Alignment of small He-Bubbles during in situ deformation of Al-foils

1978 ◽  
Vol 36 (1) ◽  
pp. 396-397
Author(s):  
E. Ruedl ◽  
P. Schiller
Keyword(s):  
Fusion Reactor ◽  
Matrix Material ◽  
Fusion Reactors ◽  
First Wall ◽  
Potential Matrix ◽  
In Situ Deformation ◽  
Α Particles ◽  
Metal Aluminium

The low Z metal aluminium is a potential matrix material for the first wall in fusion reactors. A drawback in the application of A1 is the rel= atively high amount of He produced in it under fusion reactor conditions. Knowledge about the behaviour of He during irradiation and deformation in Al, especially near the surface, is therefore important.Using the TEM we have studied Al disks of 3 mm diameter and 0.2 mm thickness, which were perforated at the centre by double jet polishing. These disks were bombarded at∽200°C to various doses with α-particles, impinging at any angle and energy up to 1.5 MeV at both surfaces. The details of the irradiations are described in Ref.1. Subsequent observation indicated that in such specimens uniformly distributed He-bubbles are formed near the surface in a layer several μm thick (Fig.1).After bombardment the disks were deformed at 20°C during observation by means of a tensile device in a Philips EM 300 microscope.

Application of cross correlation to HREM images of surfaces

1987 ◽  
Vol 45 ◽  
pp. 754-755
Author(s):  
D. E. Luzzi ◽  
L. D. Marks ◽  
M. I. Buckett
Keyword(s):  
Cross Correlation ◽  
A Priori ◽  
Matrix Material ◽  
Correlation Method ◽  
Accurate Knowledge ◽  
Complex Image ◽  
Fourier Filtering ◽  
The Matrix ◽  
Low Pass ◽  
Data Reduction Technique

As the HREM becomes increasingly used for the study of dynamic localized phenomena, the development of techniques to recover the desired information from a real image is important. Often, the important features are not strongly scattering in comparison to the matrix material in addition to being masked by statistical and amorphous noise. The desired information will usually involve the accurate knowledge of the position and intensity of the contrast. In order to decipher the desired information from a complex image, cross-correlation (xcf) techniques can be utilized. Unlike other image processing methods which rely on data massaging (e.g. high/low pass filtering or Fourier filtering), the cross-correlation method is a rigorous data reduction technique with no a priori assumptions.We have examined basic cross-correlation procedures using images of discrete gaussian peaks and have developed an iterative procedure to greatly enhance the capabilities of these techniques when the contrast from the peaks overlap.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Characterization of microwave-sintered ceramic composites

1993 ◽  
Vol 51 ◽  
pp. 1136-1137
Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek
Keyword(s):  
Matrix Material ◽  
Maximum Output Power ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Structure Characterization ◽  
Alumina Powder ◽  
Maximum Output ◽  
Sintered Ceramic

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.

Phase transformation and layer evolution in molybdenum disilicide-silicon carbide nanolayered coatings

1994 ◽  
Vol 52 ◽  
pp. 538-539
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J.-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Elevated Temperatures ◽  
Matrix Material ◽  
Molybdenum Disilicide ◽  
High Temperature Strength ◽  
Cross Sectional ◽  
Good Oxidation Resistance ◽  
Structural Applications

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.

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