Evaluation of Non-Uniform Deformation of Multi-Layered Ceramic Sheets with Printed Electrodes during Compression

2011 ◽  
Vol 418-420 ◽  
pp. 1647-1653
Author(s):  
Fumio Naruse ◽  
Naoya Tada
Keyword(s):  
Deformation Behavior ◽  
Recent Trend ◽  
Video Camera ◽  
Transverse Displacement ◽  
Compression Tests ◽  
Electronic Components ◽  
Uniform Deformation ◽  
Digital Video Camera ◽  
Layered Ceramic

With the recent trend of down-sizing and more efficient use of electric power in electric appliances, there is a growing need of smaller electronic components, such as multi-layered ceramic capacitors (MLCCs). However, it was found that the non-uniform deformation occurred in MLCC block during the pressing process and it hinders the miniaturization of MLCCs. In this study, compression tests of multi-layered ceramic sheets with printed electrodes were carried out and the deformation behavior was observed in situ and recorded by digital video camera. The change in area fraction and transverse displacement were evaluated and the deformation mechanism was inferred from the results.

On the Formability/Instability of Stretch-Forming Sheet Metals

1992 ◽  
Vol 45 (3S) ◽  
pp. S154-S164 ◽  
Author(s):  
A. E. Bayoumi ◽  
R. Joshi
Keyword(s):  
Deformation Behavior ◽  
Shear Banding ◽  
Theoretical Models ◽  
Plastic Instability ◽  
Experimental Methodology ◽  
Manufacturing Processes ◽  
Sheet Metals ◽  
Stretch Forming ◽  
Electronic Components ◽  
Uniform Deformation

Manufacturing processes of aircraft, automobile and electronic components involve a lot of stretch-forming of sheet metals. The processes contain a large amount of straining which, in turn, may lead to plastic instabilities such as necking, slip formation or shear banding. Understanding the instability phenomenon requires the development of constitutive description of material characterizing the plastic instability and post uniform deformation behavior. The previous work on plastic instability usually lacks the experimental verification of the theoretical models. This may be owing to the complexity involved in designing a suitable experimental methodology for accurate measurements of strain in the locally deforming zone as the deformation progresses rather rapidly once the local neck sets in. A review of the important methodologies and analyses that were and are used in investigating instability of sheet metal in uniaxial tension is presented in this paper. Some supporting results are also presented.

In Situ Study on the Compression Deformation Behavior of MoNbTaVW High-Entropy Alloy

2020 ◽  
Author(s):  
Congyan Zhang ◽  
Binbin Yue ◽  
Uttam Bhandari ◽  
Oleg Starovoytov ◽  
Yan Yang ◽  
...  
Keyword(s):  
Deformation Behavior ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Compression Deformation

scholarly journals Hot Workability of 300M Steel Investigated by In Situ and Ex Situ Compression Tests

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 880 ◽  
Author(s):  
Rongchuang Chen ◽  
Haifeng Xiao ◽  
Min Wang ◽  
Jianjun Li
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Hot Working ◽  
Ex Situ ◽  
Lower Strain Rate ◽  
Hot Workability ◽  
Compression Tests ◽  
300M Steel ◽  
Lower Strain

In this work, hot compression experiments of 300M steel were performed at 900–1150 °C and 0.01–10 s−1. The relation of flow stress and microstructure evolution was analyzed. The intriguing finding was that at a lower strain rate (0.01 s−1), the flow stress curves were single-peaked, while at a higher strain rate (10 s−1), no peak occurred. Metallographic observation results revealed the phenomenon was because dynamic recrystallization was more complete at a lower strain rate. In situ compression tests were carried out to compare with the results by ex situ compression tests. Hot working maps representing the influences of strains, strain rates, and temperatures were established. It was found that the power dissipation coefficient was not only related to the recrystallized grain size but was also related to the volume fraction of recrystallized grains. The optimal hot working parameters were suggested. This work provides comprehensive understanding of the hot workability of 300M steel in thermal compression.

scholarly journals Study on Microstructure and In Situ Tensile Deformation Behavior of Fe-25Mn-xAl-8Ni-C Alloy Prepared by Vacuum Arc Melting

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 814
Author(s):  
Yaping Bai ◽  
Meng Li ◽  
Chao Cheng ◽  
Jianping Li ◽  
Yongchun Guo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Vacuum Arc ◽  
Al Content ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Tensile Deformation Behavior

In this study, Fe-25Mn-xAl-8Ni-C alloys (x = 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%) were prepared by a vacuum arc melting method, and the microstructure of this series of alloys and the in situ tensile deformation behavior were studied. The results showed that Fe-25Mn-xAl-8Ni-C alloys mainly contained austenite phase with a small amount of NiAl compound. With the content of Al increasing, the amount of austenite decreased while the amount of NiAl compound increased. When the Al content increased to 12 wt.%, the interface between austenite and NiAl compound and austenitic internal started to precipitate k-carbide phase. In situ tensile results also showed that as the content of Al increased, the alloy elongation decreased gradually, and the tensile strength first increased and then decreased. When the Al content was up to 11 wt.%, the elongation and tensile strength were 2.6% and 702.5 MPa, respectively; the results of in situ tensile dynamic observations show that during the process of stretching, austenite deformed first, and crack initiation mainly occurred at the interface between austenite and NiAl compound, and propagated along the interface, resulting in fracture of the alloy.

In Situ Observation Method for Quantitative Evaluation of Solidification Phenomena and Solidification Cracks during Welding

2014 ◽  
Vol 782 ◽  
pp. 3-7
Author(s):  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kohta Kadoi ◽  
Peng Wen
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Solidification Cracking ◽  
In Situ Observation ◽  
High Speed Video Camera ◽  
Varestraint Test ◽  
Solidification Cracks ◽  
Observation Method ◽  
Solidification Crack

Solidification cracking during welding is very serious problem for practical use. Therefore, there are so many reports concerning solidification cracking. Normally, solidification cracking susceptibility of material is quantitatively evaluated using Trans-Varestraint test. On the other hand, local solidification cracking strain was tried to measure precisely using in-situ observation method, called MISO method about 30 years ago. Recently, digital high-speed video camera develops very fast and its image quality is very high. Therefore, we have started to observe solidification crack using in site observation method. In this paper, the local critical strain of a solidification crack was measured and the high temperature ductility curves of weld metals having different dilution ratios and different grain sizes to evaluate quantitatively the effects of dilution ratio and grain size on solidification cracking susceptibility by using an improved in situ observation method.

Compression of Single-Crystal Micropillars of the Γ Intermetallic Phase in the Fe-Zn System

2014 ◽  
Vol 922 ◽  
pp. 264-269 ◽  
Author(s):  
Masahiro Inomoto ◽  
Norihiko L. Okamoto ◽  
Haruyuki Inui
Keyword(s):  
Single Crystal ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Intermetallic Phase ◽  
Gamma Phase ◽  
Compression Tests ◽  
Slip Direction ◽  
Beam Method

The deformation behavior of the Γ (gamma) phase in the Fe-Zn system has been investigated via room-temperature compression tests of single-crystal micropillar specimens fabricated by the focused ion beam method. Trace analysis of slip lines indicates that {110} slip occurs for the specimens investigated in the present study. Although the slip direction has not been uniquely determined, the slip direction might be <111> in consideration of the crystal structure of the Γ phase (bcc).

Nanoclay-reinforced Polyacrylamide Composite: Synthesis, Structural and Mechanical Characterization

2009 ◽  
Vol 1239 ◽  
Author(s):  
Yong Sun ◽  
Zaiwang Huang ◽  
Xiaodong Li
Keyword(s):  
Thin Films ◽  
Deformation Behavior ◽  
Mechanical Characterization ◽  
Interfacial Strength ◽  
Localized Deformation ◽  
Nano Indentation ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Synthesized Materials

AbstractA facile electrophoretic deposition method was successfully applied to achieve novel nanoclay-reinforced polyacrylamide nanocomposite thin films. A special curled architecture of the re-aggregated nanoclay-platelets was identified, providing a possible source for realizing the interlocking mechanism in the nanocomposites. The curled architecture could be the result from strain releasing when the thin films were peeled off from the substrates. Through micro-/nano-indentation and in situ observation of the deformation during tensile test with an atomic force microscope (AFM), the localized deformation mechanism of the synthesized materials was investigated in further details. The results implied that a localized crack diversion mechanism worked in the synthesized nanocomposite thin films, which resembled its nature counterpart-nacre. The deformation behavior and fracture mechanism were discussed with reference to lamellar structure, interfacial strength between the nanoclays and the polyacrylamide matrix, and nanoclay agglomeration.

Characterization of High Temperature Deformation Behavior of BFe10-1-2 Cupronickel Alloy Using Orthogonal Analysis

2017 ◽  
Vol 36 (7) ◽  
pp. 701-710
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Xiaolu Zhang ◽  
Wen Wang
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Statistical Parameters ◽  
Orthogonal Analysis

AbstractHigh temperature deformation behavior of BFe10-1-2 cupronickel alloy was investigated by means of isothermal compression tests in the temperature range of 1,023~1,273 K and strain rate range of 0.001~10 s–1. Based on orthogonal experiment and variance analysis, the significance of the effects of strain, strain rate and deformation temperature on the flow stress was evaluated. Thereafter, a constitutive equation was developed on the basis of the orthogonal analysis conclusions. Subsequently, standard statistical parameters were introduced to verify the validity of developed constitutive equation. The results indicated that the predicted flow stress values from the constitutive equation could track the experimental data of BFe10-1-2 cupronickel alloy under most deformation conditions.

AN OBJECT LOCATION SPECIFYING METHODOLOGY USING ONE CAMERA

2001 ◽  
Vol 09 (06) ◽  
pp. 685-702 ◽  
Author(s):  
WIRAT KESRARAT ◽  
THOTSAPON SORTRAKUL
Keyword(s):  
Image Processing ◽  
Image Plane ◽  
Video Camera ◽  
Object Location ◽  
Target Point ◽  
Target Area ◽  
Digital Video Camera ◽  
The World ◽  
The Difference ◽  
Point Center

This research proposed a methodology for specifying the location of an object with image processing. The objectives of this methodology are to capture the target area, and specify the location of the object by using image. In order to locate the dropping object on the image plane efficiently, consecutive images are analyzed and a threshold operation is proposed. Because the accuracy of the dropping objects location on the difference of consecutive images image plane is usually influenced by noise. Moreover, transformation unit is adopted to map the XY coordinate on image plane into the world coordinate for an accuracy of the dropping objects position. After we get the actual XY coordinate of the dropping object, we can find the distance from the target point (center) and clock direction of the dropping object related to the center also. In addition, by using one digital video camera set on the tower and pan to capture the image on the target area to detect the dropping object from the air to the ground. It made the proposed methodology provide easier portability to detect the dropping object in any area.

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