scholarly journals Fabrication of Micro-Punch Array by Plasma Printing for Micro-Embossing into Copper Substrates

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2640
Author(s):  
Tomomi Shiratori ◽  
Tatsuhiko Aizawa ◽  
Yasuo Saito ◽  
Kuniaki Dohda
Keyword(s):  
Stainless Steel ◽  
Closed Loop ◽  
Plasma Nitriding ◽  
Testing Machine ◽  
Three Dimensional ◽  
Copper Plate ◽  
Two Dimensional ◽  
Sand Blasting ◽  
Geometric Configurations ◽  
Micro Pattern

Copper substrates were wrought to have micro-grooves for packaging by micro-stamping with use of a AISI316 stainless steel micro-punch array. The micro-texture of this arrayed punch was first tailored and compiled into CAD data. A screen film was prepared to have the tailored micro-pattern in correspondence to the CAD data. A negative pattern to this screen was printed directly onto the AISI316 die substrate. This substrate was plasma nitrided at 673 K for 14.4 ks. The unprinted die surfaces were selectively nitrogen super-saturated to have sufficiently high corrosion toughness and hardness; other surfaces were masked by the prints. The two-dimensional micro-pattern on the screen was transformed into a three-dimensional nitrogen supersaturated micro-texture embedded in the AISI316 die. The printed surfaces were selectively sand-blasted to fabricate the micro-textured punch array for micro-embossing. A uniaxial compression testing machine was utilized to describe the micro-embossing behavior in copper substrates and to investigate how the micro-texture on the die was transcribed to the copper. The micro-punch array in this study consisted of three closed loop heads with a width of 75 µm and a height of 120 µm after plasma nitriding and sand-blasting. Since the nitrogen supersaturated heads had sufficient hardness against the blasting media, the printed parts of AISI316 die were removed. The micro-embossing process was described by comparison of the geometric configurations between the multi-punch array and the embossed copper plate.

Evaluation of Residual Stresses in Small Diameter Stainless Steel Pipe Welds by Two-Dimensional and Three-Dimensional Finite Element Analyses

2014 ◽  
Author(s):  
Francis H. Ku ◽  
Trevor G. Hicks ◽  
William R. Mabe ◽  
Jason R. Miller
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Steel Pipe ◽  
3D Analysis ◽  
Two Dimensional ◽  
Finite Element Analyses ◽  
Stainless Steel Pipe

Two-dimensional (2D) and three-dimensional (3D) weld-induced residual stress finite element analyses have been performed for 2-inch Schedule 80 Type-304 stainless steel pipe sections joined by a multi-layer segmented-bead pipe weld. The analyses investigate the similarities and differences between the two modeling approaches in terms of residual stresses and axial shrinkage induced by the pipe weld. The 2D analyses are of axisymmetric behavior and evaluate two different pipe end constraints, namely fixed-fixed and fixed-free, while the 3D analysis approximates the non-axisymmetric segmented welding expected in production, with fixed-free pipe end constraints. Based on the results presented, the following conclusions can be drawn. The welding temperature contour results between the 2D and 3D analyses are very similar. Only the 3D analysis is capable of simulating the non-axisymmetric behavior of the segmented welding technique. The 2D analyses yield similar hoop residual stresses to the 3D analysis, and closely capture the maximum and minimum ID surface hoop residual stresses from the 3D analysis. The primary difference in ID surface residual stresses between the 2D fixed-fixed and 2D fixed-free constraints cases is the higher tensile axial stresses in the pipe outside of the weld region. The 2D analyses under-predict the maximum axial residual stress compared to the 3D analysis. The 2D ID surface residual stress results tend to bound the averaged 3D results. 2D axisymmetric modeling tends to significantly under-predict weld shrinkage. Axial weld shrinkage from 3D modeling is of the same magnitude as values measured in the laboratory on a prototypic mockup.

scholarly journals Performance Characteristics of Two- and Three-Dimensional Impellers in Centrifugal Compressors

1986 ◽  
Author(s):  
H. Harada
Keyword(s):  
Centrifugal Compressor ◽  
Closed Loop ◽  
Three Dimensional ◽  
Performance Characteristics ◽  
Working Fluid ◽  
Angle Distribution ◽  
Two Dimensional ◽  
Blade Angle ◽  
Operating Range ◽  
Overall Performance

The overall performance of two- and three-dimensional impellers of a centrifugal compressor were tested and compared. A closed loop test stand with Freon gas as working fluid was employed for the experiments. The inlet and outlet velocity distribtions of all impellers were measured using three hole cobra probes. As a result, it has been revealed that three-dimensional impellers are superior to two-dimensional one in terms of efficiency, head coefficient and operating range. Further, it has also been clarified that the impeller slip factor is affected by blade angle distribution.

A Study of Cyclic Thermal Straining in a Welded Joint, Using a Closed-Loop, Servo-Controlled Testing Machine

1992 ◽  
Vol 114 (4) ◽  
pp. 422-427 ◽  
Author(s):  
Y. Z. Itoh ◽  
H. Kashiwaya
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Thermal Stress ◽  
Residual Stresses ◽  
Closed Loop ◽  
Thermal Stresses ◽  
Testing Machine ◽  
Step Test ◽  
Transient Thermal ◽  
Incremental Step

For investigating the origin of residual stresses in welded joints, the transient thermal stresses in a carbon-manganese-silicon steel (JIS SM41B), a cast martensitic stainless steel (JIS SCS5), an austenitic stainless steel (JIS SUS304), and a titanium alloy (Ti-6Al-4V) were investigated by subjecting round bar specimens, in which both ends were fixed, to thermal of cycles. The specimens were heated in air by high-frequency induction. The cyclic thermal straining tests were conducted for the case of a single thermal cycle and the case of multiple thermal cycles, using a closed loop, servo-controlled testing machine. The experimental results made clear that the transient thermal stress behavior was dependent on metallurgical effects, such as phase transformations, strain hardening, the Bauschinger effect, etc. The effects on phase transformation on the transient thermal stress behavior of SCS5 and SM41B were especially remarkable. However, the effects of phase transformations on the residual stresses due to the thermal straining cycle were negligible in SM41B and not observed in both SUS304 and Ti-6Al-4V. The residual stresses tended to increase with increase of the peak temperature of thermal cycles in SM41B, SUS304 and Ti-6Al-4V. However, when the peak temperature increased above 600°C in SCS5, the residual stress rapidly decreased and became compressive because of the expansion due to the martensite transformation. This study led to the conclusion that the transient thermal stresses for various peak temperatures could easily be obtained by an incremental step test using a single specimen and that this incremental step test could simply estimate the residual stress character of butt-welded joints.

Enhancement of wear resistance by sand blasting-assisted rapid plasma nitriding for 304 austenitic stainless steel

2019 ◽  
Vol 36 (5) ◽  
pp. 524-530
Author(s):  
Dong Li ◽  
Jiqiang Wu ◽  
Bin Miao ◽  
Xiaobing Zhao ◽  
Changjun Mao ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Austenitic Stainless Steel ◽  
Plasma Nitriding ◽  
Sand Blasting ◽  
304 Austenitic Stainless Steel

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

Comparison of Recovery and Recrystallization in Stainless Steel Following Plane-Wave Shock Loading and Explosive Forming

1970 ◽  
Vol 28 ◽  
pp. 428-429 ◽  
Author(s):  
J. A. Korbonski ◽  
L. E. Murr
Keyword(s):  
Stainless Steel ◽  
Shock Loading ◽  
Pressure Pulse ◽  
Shock Pressure ◽  
304 Stainless Steel ◽  
Strain Rates ◽  
Two Dimensional ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Explosive Forming

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

An Image Reconstruction System Applied to High Voltage Microscopy

1975 ◽  
Vol 33 ◽  
pp. 292-293
Author(s):  
D. E. Johnson
Keyword(s):  
High Voltage ◽  
Prior Information ◽  
Block Diagram ◽  
Three Dimensional ◽  
Real Space ◽  
Two Dimensional ◽  
Efficient Manner ◽  
Fourier Methods ◽  
Tilt Series ◽  
Methods Of Reconstruction

Increased specimen penetration; the principle advantage of high voltage microscopy, is accompanied by an increased need to utilize information on three dimensional specimen structure available in the form of two dimensional projections (i.e. micrographs). We are engaged in a program to develop methods which allow the maximum use of information contained in a through tilt series of micrographs to determine three dimensional speciman structure.In general, we are dealing with structures lacking in symmetry and with projections available from only a limited span of angles (±60°). For these reasons, we must make maximum use of any prior information available about the specimen. To do this in the most efficient manner, we have concentrated on iterative, real space methods rather than Fourier methods of reconstruction. The particular iterative algorithm we have developed is given in detail in ref. 3. A block diagram of the complete reconstruction system is shown in fig. 1.

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