scholarly journals Fabrication of aluminum bipolar plates with Archimedes' screw-shaped channels: a rubber pad forming process assessment

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
S. J. Hashemi ◽  
Amir H. Roohi
Keyword(s):  
Natural Rubber ◽  
Hydraulic Press ◽  
Process Assessment ◽  
Bipolar Plates ◽  
Channel Depth ◽  
Forming Process ◽  
Punch Speed ◽  
Draft Angle ◽  
Rubber Pad Forming ◽  
Very High

AbstractBipolar plates are one of the most important components of polymer membrane fuel cells. In this manuscript, the rubber pad forming of aluminum bipolar plates with Archimedes' screw-shaped channels and draft angle of 90$$^\circ$$ ∘ has been investigated. Hence, all possible combinations of the process parameters were determined and corresponding experimentations performed in order to investigate the effects of the rubber hardness, punch speed and the hydraulic press force. In this regard, three rubber pads including polyurethane, silicone and natural rubber were used. Channel depth and thinning percentage in the corner of the channel are measured and the effect of each parameter is analyzed. Based on the results, the maximum channel depth was achieved using a silicone pad with a hardness of 60 Shore A. Using a rubber pad with a very high and low hardness number, both, reduces the depth of channel. Furthermore, as the punch speed increases, the channel depth increases and the thinning percentage, as well.

The Fabrication of a Micro-Channel for Metallic Bipolar Plates Using a Rubber Pad Forming Process

2014 ◽  
Vol 626 ◽  
pp. 16-26 ◽  
Author(s):  
You Min Huang ◽  
Yi Syun Wu ◽  
Shung Ping Wang
Keyword(s):  
Thickness Distribution ◽  
Flow Distribution ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Channel Height ◽  
Bipolar Plates ◽  
Forming Process ◽  
Element Analysis ◽  
Metallic Bipolar Plates ◽  
Rubber Pad Forming

A bipolar plate is one the most crucial and costliest of the various components of a proton exchange membrane fuel cell (PEMFC). It is important to reduce the cost of bipolar plate, not only in terms of material, but also in terms of the manufacturing process, to allow the commercialization of PEMFC’s. The performance of PEMFC’s is also of importance. Metallic bipolar plates have been the subject of much attention recently, because of their low material cost, formability and excellent thermal and mechanical prosperities. Therefore, this study uses a rubber pad forming process for stainless 316L steel to fabricate a bipolar plate with serpentine channels. A computational fluid dynamics (CFD) analysis is performed, in order to determine the influence of channel geometries, such as channel width, channel height and rib width, on the flow distribution of the reactant. Using the CFD results, finite element analysis models are then constructed and the formability of the micro-flow channel is studied. Finality, experiments are conducted to determine the channel height and thickness distribution of the bipolar plate. The numerical results are verified by the experimental results.

scholarly journals Investigation of Bipolar Plate Forming with Various Die Configurations by Magnetic Pulse Method

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 453 ◽  
Author(s):  
Wang ◽  
Wang
Keyword(s):  
Major Part ◽  
Capacitor Bank ◽  
Pulse Method ◽  
Bipolar Plate ◽  
Magnetic Pulse ◽  
Percentage Increase ◽  
Bipolar Plates ◽  
Draft Angle ◽  
Die Surface ◽  
Primary Current

Bipolar plates are a major part of fuel cells, which are a clean and recyclable energy source. This study was carried out with two dies for a bipolar plate forming investigation with the magnetic pulse method: a bipolar plate die and a 10-channel die. With the bipolar plate die, the forming of bipolar plates with a Cu110 sheet and a Grade 2 Ti sheet indicated that the bipolar plate die needed optimization for a full replication. The obtained maximum average depth percentage was 86% for a Cu110 sheet, while it was 54% for a Grade 2 Ti sheet in this study. A further increase of the depth percentage is possible but requires a much higher capacitor bank energy. The increase of the capacitor bank energy would result in severe tearing, while the depth percentage increase was little. The primary current and flyer velocity were measured at various capacitor bank energies. With the 10-channel die, the die parameters’ effect on metal sheet forming was investigated with a Cu110 sheet and an SS201 sheet. The draft angle had a significant effect on the replication of the die surface. The full replication was achieved for channels with proper parameters with both a Cu110 sheet and an SS201 sheet. Therefore, the bipolar plate die could be optimized based on the 10-channel die results.

scholarly journals XIV. On the absorption of gases by solids

1881 ◽  
Vol 32 (212-215) ◽  
pp. 407-408
Keyword(s):  
Royal Society ◽  
Hydraulic Press ◽  
Careful Examination ◽  
Solid Matter ◽  
Chemical Action ◽  
High Pressure And Temperature ◽  
Solid Iron ◽  
Series Of Experiments ◽  
The Subject ◽  
Very High

During the progress of the investigations which I have from time to time had the honour of bringing under the notice of the Royal Society, I have again and again noticed the apparent disappearance of gases inclosed in vessels of various materials when the disappearance could not be accounted for upon the assumption of ordinary leakage. After a careful examination of the subject I found that the solids absorbed or dissolved the gases, giving rise to a striking example of the fixation of a gas in a solid without chemical action. In carrying out that most troublesome investigation, the crystalline separation of carbon from its compounds, the tubes used for experiment have been in nine cases out of ten found to be empty on opening them, and in most cases a careful testing by hydraulic press showed no leakage. The gases seemed to go through the solid iron, although it was 2 inches thick. A series of experiments with various linings were tried. The tube was electro-plated with copper, silver, and gold, but with no greater success. Siliceous linings were tried fusible enamels and glass—but still the' tubes refused to hold the contents. Out of thirty-four experiments made since my last results were published, only four contained any liquid or condensed gaseous matter after the furnacing. I became convinced that the solid matter at the very high pressure and temperature used must be pervious to gases.

Finite Element Simulation and Experimental Study on Isothermal Forging Technology for a Complex-Shaped Titanium Alloy Wing

2013 ◽  
Vol 575-576 ◽  
pp. 523-526
Author(s):  
Feng Cheng ◽  
Hong Yan Jiang
Keyword(s):  
Titanium Alloy ◽  
Variable Cross Section ◽  
Hydraulic Press ◽  
Asymmetric Structure ◽  
Variable Cross ◽  
Forming Process ◽  
Isothermal Forging ◽  
Filling Ability ◽  
Simulation Results ◽  
Mechanical Performances

A closed isothermal forging process was adopted for precision forming of the Ti-6Al-4V wing with a variable cross-section asymmetric structure. Firstly, simulations under different process parameters, such as the deformation temperature, punchs velocity et al. were analyzed with DEFORM-3D software to eliminate the defects in the isothermal forming process. The simulation results demonstrated that the loads during isothermal deformation were determined not just by the forging temperature but the punchs velocity, the less velocity of punch, the better filling ability, and yet temperatures from 900 to 950°C had less influence on filling ability. To verify the validity of simulation results, the isothermal forging experiment was carried out on an isothermal forging hydraulic press (THP10-630). It is demonstrated that the optimized billet dimension can ensure the quality of forging part and the titanium alloy wing component with complex shape was successfully forged with the punch speed of 0.1mm/s at 950°C and its mechanical performances were improved.

Simulation and experiment researches on rubber pad forming of two-step channels by different dies

2021 ◽  
pp. 095440622110342
Author(s):  
Teng Fei ◽  
Wang Hongyu ◽  
Wang Guodong ◽  
Jiang Lei ◽  
Sun Juncai ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Design Strategy ◽  
Forming Process ◽  
Processing Technologies ◽  
Physical Experiments ◽  
Micro Channels ◽  
Rubber Pad Forming ◽  
Simulation And Experiment

Rubber pad forming is one of advance processing technologies. With both rubber pad and die, the sheet metal is stamped into the required shapes. The shapes of the die directly affect the final shapes of the channels on the sheet. With the developments of micro-channels, a new kind of two-step channels is concerned gradually in many fields. Since there are waved structures in these channels, many beneficial functions are caused. However, the manufacturing of this new kind channels by rubber pad forming are still not meticulously researched. This article is focused on the rubber pad forming process of different two-step channels. Different two-step channels are designed and made. Based on both FEM and physical experiments, the forming processes of these new channels are researched. The forming results are discussed and compared with each other, the best design strategy is also proposed through results.

Thickness analysis of complex two-step micro-groove on plate during rubber pad forming process

2020 ◽  
pp. 095440622093392
Author(s):  
Fei Teng ◽  
Hongyu Wang ◽  
Juncai Sun ◽  
Xiangwei Kong ◽  
Jie Sun ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thickness Variation ◽  
Forming Process ◽  
Rubber Pad Forming ◽  
Groove Structure ◽  
Thickness Variations ◽  
Accuracy Of Results ◽  
Plane Slab ◽  
Element Method

The surface groove structure has numerous functions based on their shapes. In order to make these functions developed, both new shapes and processing forms of the surface structures are being innovated. In this paper, not only the advanced rubber pad forming process is used, but also a new kind of micro-groove with two-step structures is designed. A model based on multi-plane slab method is proposed to analyze the process. According to the stress acting condition, a half of two-step micro-groove structure is divided into seven areas in the width direction. The thickness variation of plate in each area is obtained. When the shape, depth, width, and height ratio of the first and second-step micro-groove are different, the thickness variations of the plate are analyzed. In order to verify the accuracy of the model, both finite element method and pressing experiment are done. Based on the results provided by both finite element method and experiment, the accuracy of results calculated by analytical model is verified.

scholarly journals Carbon Nanotube Reinforced Natural Rubber Nanocomposite for Anthropomorphic Prosthetic Foot Purpose

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rasaq Olawale Medupin ◽  
Oladiran Kamardeen Abubakre ◽  
Ambali Saka Abdulkareem ◽  
Rasheed Aremu Muriana ◽  
Asipita Salawu Abdulrahman
Keyword(s):  
Carbon Nanotube ◽  
Natural Rubber ◽  
Polymer Nanocomposite ◽  
Mechanical Analysis ◽  
Hydraulic Press ◽  
Prosthetic Material ◽  
Segmental Motion ◽  
Ambient Conditions ◽  
Prosthetic Foot ◽  
Microstructure Examination

AbstractThis research is motivated by the desire to restore the quality of life to amputees. The study uses multi-walled carbon nanotube (WMCNT) reinforced natural rubber (NR) polymer nanocomposite (PNC) for prosthetic foot application. The compound formulation was carried out in accordance to a modified procedure described by Hemkaew et al. Mixing of the ingredients during vulcanisation was performed according to ASTM D-3182 standard on an open two-roll mill. The various compositions of the nanocomposites (NCs) were cured at a temperature of 150 ± 2 °C and a pressure of 0.2 MPa for 10 minutes in an electrically heated hydraulic press. Mechanical investigation revealed that NR/MWCNT-3 exhibited the highest capacity to withstand tensile and dynamic loading (449.79 MPa). It also showed superior filler distribution and hence improved crystallinity and cross-link. Water absorption test indicated that NR/MWCNT-3 offers optimum dimensional stability at ambient conditions. Moreover, thermogravimetric analysis/differential thermogravimetry (TGA/DTG) showed degradation peaks at 305 °C and 290 °C respectively with temperature range within which the NCs degraded lying between 250 °C and 600 °C. Dynamic mechanical analysis (DMA) revealed that filler incorporation results in higher storage and loss moduli (2000–7500 MPa and 500–1413 MPa respectively). Tan δ curves proved that NR/MWCNT-3 has the highest capacity to dissipate energy through segmental motion. Furthermore, microstructure examination confirmed good filler/matrix adhesion as NR/MWCNT-3 indicated improved interaction; hence higher strength (6.02 MPa) of the NC. Better wear resistance ability can also be reported of the newly developed than existing prosthetic material. It can be deduced that the formulated nanocomposite from MWCNTs for reinforced natural rubber is suitable for the development of the anthropomorphic prosthetic foot.

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