Effects of Grain Size and Lubricating Conditions on Micro Forward and Backward Hollow Extrusion of Brass

2013 ◽  
Vol 479-480 ◽  
pp. 8-12 ◽  
Author(s):  
Chao Cheng Chang ◽  
Cheung Hwa Hsu ◽  
Jian Cheng Lai
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Friction Factor ◽  
Metal Forming ◽  
Material Flow ◽  
Outer Diameter ◽  
Grain Sizes ◽  
Friction Factors ◽  
Dry Conditions ◽  
Inner Diameter

Grain size and lubricating conditions influence material flow behaviours in micro metal forming processes. In this study, the brass (JIS C2700) tubes with 1.1 mm outer diameter and 0.5 mm inner diameter were treated by annealing at 400 °C, 500 °C and 600 °C to obtain various microstructures with the grain sizes of 20 μm, 34 μm and 80 μm, respectively. The treated tubes were machined and grounded to be 0.6 mm length specimens for the experiments of micro forward and backward hollow extrusion. Three lubricating conditions, which were dry, full and punch lubricated conditions, were carried out in the experiments. By comparing the upper cup height and rod length of the extruded specimens with the calibration curves established by finite element simulations, it is possible to estimate the friction factors in the processes. The results show that the dry conditions lead to stronger friction effects and thus larger friction factors. Moreover, the friction factor increased with grain size and stroke for all conditions.

scholarly journals Effect of lubrication and friction coefficient on temperature distribution for combined backward forward extrusion process for alloy steel

2018 ◽  
Vol 1 (1) ◽  
pp. 352-357
Author(s):  
Ban Alamer ◽  
Çetin Karataş ◽  
Faruk Mert ◽  
Haitham Aljawad
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Distribution ◽  
Numerical Analysis ◽  
Friction Coefficient ◽  
Friction Factor ◽  
Metal Forming ◽  
Extrusion Process ◽  
Forward Extrusion ◽  
Friction Factors

During extrusion process ,the effects of friction between die and workpiece are important and it is one of the most serious problems in metal forming. Friction factor has different effects depending on the size of workpiece. In this study the effect of friction factor and lubrication effects on temperature distribution , power , and load for combined backward forward extrusion process was demonstrated . A numerical analysis based on finite element method by using Q form program was used to study the effect of friction factor through two type of condition , first for lubrication three values for friction factor were used ( 0.1, 0.2 ,0.3 ) .The second condition was un lubrication , the friction factors values were (0.25 , 0.5 ,0.75) . The material of specimen was steel C45.The parts to be manufactured was wrench socket and the lubrication was done by using water and graphite .The results showed that for lubricated and un lubricated conditions , the temperatures power and load were increased when the friction factor increased .

Eulerian FEA With Volume of Solid (VOS) Application in Metal Forming

2010 ◽  
Author(s):  
K. S. Al-Athel ◽  
M. S. Gadala
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Process Improvement ◽  
Metal Forming ◽  
Material Flow ◽  
Solid Mechanics ◽  
Uniform Mesh ◽  
Element Formulation ◽  
Volume Of Fluid Method ◽  
Whole Process

The adaptation of the volume of fluid method (VOF) to solid mechanics (VOS) is presented in this work with the focus on metal forming applications. The method is discussed for a general non-uniform mesh with Eulerian finite element formulation. The implementation of the VOS method in metal forming applications is presented by focusing on topics such as the contact between the tool and the workpiece, tracking of the free surface of the material flow and the connectivity of the free surface during the whole process. Improvement on the connectivity of the free surface and the representation of curves is achieved by considering the mechanics of different metal forming processes. Different applications are simulated and discussed to highlight the capability of the VOS method.

A Study on Warm Micro Backward Extrusion of SUS 304 Stainless Steel

2011 ◽  
Vol 486 ◽  
pp. 139-142
Author(s):  
Chao Cheng Chang ◽  
Dinh Hiep Nguyen ◽  
Hsin Sheng Hsiao
Keyword(s):  
Stainless Steel ◽  
Metal Forming ◽  
Material Flow ◽  
Elevated Temperatures ◽  
304 Stainless Steel ◽  
Electrical Heater ◽  
Backward Extrusion ◽  
Water Based ◽  
Inner Diameter ◽  
The One

A metal forming system comprising an electrical heater, capable of conducting processes at elevated temperatures, was developed to perform micro backward extrusion processes of SUS 304 stainless steel. Two punches with diameters of 1.6 mm and 1.8 mm were used to extrude the billets inside the die with an inner diameter of 2 mm. All processes were lubricated with water-based graphite and conducted under isothermal conditions at 400 °C. The results show that the developed extrusion system can be used to produce the stainless steel components with a micro cup-shaped profile. Moreover, the variation in the rim height of the cups produced by the 1.8 mm diameter punch is greater than the one by the 1.6 mm diameter punch. The results show that a decrease in the clearance between the punch and die could lead to an increase in the inhomogeneity of material flow in the micro backward extrusion processes.

Effective Forming Processes of Hub Forging from Aluminum Alloy AlCu2SiMn

2013 ◽  
Vol 773-774 ◽  
pp. 115-118
Author(s):  
Andrzej Gontarz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Metal Forming ◽  
Material Flow ◽  
Theoretical Research ◽  
Material Consumption ◽  
Forming Process ◽  
Metal Forming Process ◽  
Large Material

This paper presents results of theoretical and experimental research works on metal forming process of a hub. A typical technology of forging on hammer of this part with flash was discussed. Two new processes of a hub forging were proposed, characterized by large material savings in comparison with typical technology. The first process is based on forming without flash of a forging with axial cavity. The second one is connected with forming of forging from pipe billet. The realization of these processes is possible at the application of a press with three movable working tools. Theoretical research works were done on the basis of simulations by means of finite element method. Simulations were made mainly in order to determine kinematics of material flow in forging processes and precision of shape and dimensions of obtained products. The first of the proposed processes was experimentally verified and a product of good quality was obtained. Material consumption of the analyzed processes and other factors acting on their effectiveness were also compared.

scholarly journals EFFECT OF TUBE DIAMETER AND SURFACE ROUGHNESS ON FLUID FLOW FRICTION FACTOR

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
M. Mirmanto ◽  
IGNK Yudhyadi ◽  
Emmy Dyah Sulistyowati
Keyword(s):  
Stainless Steel ◽  
Friction Factor ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
Fluid Friction ◽  
Friction Factors ◽  
Average Grain Size ◽  
Experimental Apparatus ◽  
Inner Diameter ◽  
Different Diameters

Experiments have been performed to investigate the effect of channel roughness and diameter on fluid friction. Three different diameters and roughness of tubes were used to examine the friction factor. The first tube made of stainless steel with an inner diameter of 1.14 mm was investigated at Brunel University, whilst the others made of PVC with diameters of 17 mm and 15.5 mm rough were tested at Mataram University. The stainless steel was equipped with a 200 mm calming section and smooth one. The 15.5 mm diameter tube was coated internally with sand that had an average grain size of 0.5 mm so that the tube had a relative roughness of 0.032.  The last tube with a diameter of 17 mm was smooth as explained  in the H408 Fluid Friction Experimental Apparatus manual.            The results indicate that the flow in the stainless steel tube still obeys the theory and in the 17 mm tube shows a deviation in friction factor with the theory. However, this was due to no calming section installed in the test rig. Flow in the rough tube (15.5 mm diameter) demonstrates that the Reynolds number does not affect the friction factor in turbulent regimes and the experimental friction factors were reasonably in a good agreement with the theory or Moody diagram. Hence, the effect of decreasing in diameter of channels on friction factor is insignificant.

Effective Forming Processes of Hub Forging from Aluminum Alloy AlCu2SiMn

2013 ◽  
Vol 572 ◽  
pp. 265-268
Author(s):  
Andrzej Gontarz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Metal Forming ◽  
Material Flow ◽  
Theoretical Research ◽  
Material Consumption ◽  
Forming Process ◽  
Metal Forming Process ◽  
Large Material

This paper presents results of theoretical and experimental research works on metal forming process of a hub. A typical technology of forging on hammer of this part with flash was discussed. Two new processes of a hub forging were proposed, characterized by large material savings in comparison with typical technology. The first process is based on forming without flash of a forging with axial cavity. The second one is connected with forming of forging from pipe billet. The realization of these processes is possible at the application of a press with three movable working tools. Theoretical research works were done on the basis of simulations by means of finite element method. Simulations were made mainly in order to determine kinematics of material flow in forging processes and precision of shape and dimensions of obtained products. The first of the proposed processes was experimentally verified and a product of good quality was obtained. Material consumption of the analyzed processes and other factors acting on their effectiveness were also compared.

The Potential and Application Areas of Forging Aided by Shear Stress

2013 ◽  
Vol 212 ◽  
pp. 91-94
Author(s):  
Marek Tkocz ◽  
Zdzisław Cyganek ◽  
Franciszek Grosman
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Finite Element Model ◽  
Numerical Simulations ◽  
Metal Forming ◽  
Material Flow ◽  
Strain Distribution ◽  
Vertical Motion ◽  
Element Model ◽  
Local Strains

The paper demonstrates the potential of unconventional metal forming method that consists in introducing shear stress at the die/workpiece interface during compression. In practice it can be realized by induction of reciprocating, vertical motion of a punch that adheres strongly to a workpiece. To estimate an effect of the method on the material flow, a relevant finite element model has been developed and the selected results of numerical simulations are presented in the paper. In comparison to the conventional forging, forming aided by shear stress is able to provide a number of benefits such as significant increase of local strains, lower press loads and the opportunity to control the strain distribution in the workpiece volume. Perspectives for continuation of the studies as well as possible application areas of forging aided by shear stress are discussed in the summary.

The Effect of Grain Size on the Quality of Micro-Stamping of the Pure Titanium TA1 Foil by Finite Element Simulation

2019 ◽  
Vol 971 ◽  
pp. 3-8
Author(s):  
Rui Chen ◽  
Hong Mei Zhang ◽  
Chang Shun Wang ◽  
Ling Yan ◽  
Yan Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Surface Morphology ◽  
Finite Element Simulation ◽  
Pure Titanium ◽  
Grain Sizes ◽  
Good Surface ◽  
Element Simulation ◽  
Simulation Results

Pure titanium TA1 foil with a thickness of 0.05mm under different grain sizes were carried out by the DT-C539 micro-stamping machine in the laboratory. The size effect of the pure titanium TA1 foil with grain sizes of 3, 7, 9 and 23 microns respectively on surface morphology of the microstamping sample were studied. It is found that the stamping samples with good surface quality can be obtained on the condition that the grain size is 23 microns and the stamping speed is 1mm/s. VORONOI model was established by using ABAQUS, NEPER and MATLAB software. Heterogeneous finite element simulation was carried out for the micro-stamping process under the same conditions. The results showed that the simulation results were more consistent with the experimental results.

Flow and Heat Transfer in 0.0196mm Quartz Microtube

2008 ◽  
Author(s):  
Zhigang Liu ◽  
Ning Guan ◽  
Masahiro Takei
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Factor ◽  
Working Fluid ◽  
Nitrogen Gas ◽  
Average Temperature ◽  
Flow And Heat Transfer ◽  
Friction Factors ◽  
Layer Effect ◽  
Inner Diameter

The flow and the heat transfer characteristics in quartz microtube with inner diameter of 0.0196mm are investigated experimentally. By measuring the pressure drop between the inlet and outlet of microtube with different working fluid and the average temperature of microtube wall heated by steam, the corresponding friction factors and Nusselt number are obtained. The experimental results show the friction factors in microtubes exceeds the prediction of Hagen-Poiseulle due to the predominance of the electrical double layer effect (EDL effect) when the working fluid is distilled water, and the experimental Nusselt number is less than the classical laminar at Reynolds number<500 due to the effects of the variation of the thermophysical properties with temperature and the conjugate heat transfer. However, the effect of viscous dissipation results in temperature rise of the working fluid, due to which the friction factors are less than the prediction of Hagen-Poiseulle with the working fluid of tetrachloromethane. Using nitrogen gas as the working fluid, the rarefaction effect still brings on that the friction factor is less than the classical laminar solution, though gas density and viscosity increases resulted from the stagnant velocity between gas and inner wall and the viscous heating lead to the increase of friction factor.

scholarly journals Scale-Dependent Dielectric Properties in BaZr0.05Ti0.95O3 Ceramics

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4386
Author(s):  
Leontin Padurariu ◽  
Vlad-Alexandru Lukacs ◽  
George Stoian ◽  
Nicoleta Lupu ◽  
Lavinia Petronela Curecheriu
Keyword(s):  
Finite Element Method ◽  
Grain Size ◽  
Finite Element ◽  
Dielectric Properties ◽  
Critical Size ◽  
Grain Sizes ◽  
Maximum Value ◽  
Doped Barium Titanate ◽  
Numerical Finite Element ◽  
Titanate Ceramics

In the present work, BaZr0.05Ti0.95O3 ceramics with grain sizes between 0.45 and 135 µm were prepared by solid-state reaction and classical sintering. The effect of grain size on dielectric properties was systematically explored, and it was found that dielectric permittivity reaches a maximum value for grain sizes between 1.5 and 10 µm and then rapidly drops for larger grain sizes. A numerical finite element method was employed to eliminate the effect of porosity on the effective values of permittivity. The results indicate that it is possible to have a critical size in slightly doped barium titanate ceramics with enhanced functional properties for a grain size between 1.5 and 10 µm.

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