scholarly journals Study on Size-Related Product Quality of Multiscale Central-Punched Cups Fabricated by Compound Forming Directly Using Brass Sheet

2022 ◽  
Author(s):  
Dien Hu ◽  
Jun-Yuan Zheng ◽  
M. W. Fu
Keyword(s):  
Grain Size ◽  
Deep Drawing ◽  
Material Flow ◽  
Dimensional Accuracy ◽  
Thickness Variation ◽  
Forming Process ◽  
Ultimate Deformation ◽  
Physical Experiments ◽  
Deformation Behaviors ◽  
Brass Sheet

Abstract Meso/microforming has gained much more attention in the last decades and is widely used as a reliable method to fabricate meso/micro-scaled metallic components. In this research, a compound meso/microforming system which combines deep drawing, punching and blanking operations was developed to fabricate multiscale central-punched cups by using brass sheets. The parts with three scales were produced by using the brass sheets with various thicknesses and grain sizes to investigate geometrical and grain size effects on the deformation behaviors, dimensional accuracy, and material flow behaviors in the forming process. Through physical experiments and finite element simulations, it is revealed that the ultimate deformation load in the drawing-punching stage is smaller than that in the single deep drawing stage under microscale, but the results in the meso-scaled scenarios are opposite. In addition, the thickness variation is increased with grain size, but the variation of the normalized thickness variation does not show an obvious tendency with different size scales. In the bending area, the material flow is tangential to the thickness direction, leading to the formation of thinning area. In addition, the material flow is almost opposite to the punching direction in the punching area, avoiding the expanding deformation of the hole. Thus, the punching operation barely affects the dimensional accuracy including the thickness and hole diameter of the formed parts. Furthermore, the micro-scaled cups with finer grains have a better surface quality. These findings enhance the understanding of size effect in compound meso/microforming with the combined deep drawing and punching operations.

Progressive and Compound Forming for Producing Plunger-Typed Microparts by Using Sheet Metal

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Jun-Yuan Zheng ◽  
Ming-Wang Fu
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Sheet Metal ◽  
Mass Production ◽  
Grain Size Effect ◽  
Sheet Metals ◽  
Forming Process ◽  
Deformation Behaviors ◽  
Progressive Forming ◽  
Insight Into

Abstract The plunger part in temporary electronic connectors is traditionally fabricated by micromachining. Progressive forming of microparts by directly using sheet metals is developed and proven to be an efficient microforming process to overcome some intrinsic drawback in realization of mass production of microparts. By employing this unique micromanufacturing process, an efficient approach with progressive microforming is developed to fabricate plunger-shaped microparts. In this endeavor, a progressive forming system for making microplungers using extrusion and blanking operations is developed, and the grain size effect affected deformation behaviors and of surface qualities of the microformed parts are studied. The knowledge for fabrication of plunger-shaped microparts via progressive microforming is developed, and the in-depth understanding and insight into the deformation behaviors and tailoring the product quality and properties will facilitate the design and development of the forming process by using this unique microforming approach.

Thickness of Magnesium Alloy Cylindrical Cup in Pressure-Lubricating Deep Drawing

2012 ◽  
Vol 189 ◽  
pp. 147-151
Author(s):  
Xian Chang Mao ◽  
Hai Yan Lin
Keyword(s):  
Magnesium Alloy ◽  
Wall Thickness ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
Blank Holder Force ◽  
Technological Parameters ◽  
Forming Process ◽  
Blank Holder ◽  
Deformation Behaviors ◽  
Cylindrical Cup

Forming process of AZ31B magnesium alloy cup parts in pressure-lubricating deep drawing was simulated by Dynaform at room temperature. The technological parameters which influence the wall thickness difference of cup parts were investigated in this paper, including internal pressure, blank holder force and punch corner radius, etc. Compared with the deformation behaviors of magnesium alloy in mechanical deep drawing and pressure-lubricating deep drawing, the wall thickness distribution of cup parts was discussed. The result shows that preferable deformation behaviors can be obtained in pressure-lubricating deep drawing when adopted adaptive technological parameters.

scholarly journals A Review of Progressive and Compound Forming of Bulk Microparts by Using Sheet Metals

2018 ◽  
Vol 190 ◽  
pp. 01001 ◽  
Author(s):  
M.W. Fu ◽  
J.Y. Zheng ◽  
B. Meng
Keyword(s):  
Size Effect ◽  
Sheet Metal ◽  
Material Flow ◽  
Dimensional Accuracy ◽  
Promising Method ◽  
Sheet Metals ◽  
Forming Process ◽  
Geometrical Feature

In the last decade, the concept of progressive microforming has emerged and developed gradually, which is considered as an efficient and promising method to fabricate the micro-scaled part. Micro-cylinder parts, micro-flanged part, and multi-flanged microparts are representative micro bulk parts by the progressive microforming system using sheet metal. In these cases, many efforts focus on the forming process, such as microblanking and microextrusion. Meanwhile, the quality of the fabricated parts also attracts attention. In this paper, an intensive review on the development of progressive microforming technologies and the formed parts is presented, and the influence of size effect to dimensional accuracy, material flow, geometrical feature, and fracture is also discussed.

Research on the Application of Expansion Ratio Analysis for Die-Face Optimal Design in Sheet Metal Forming

2011 ◽  
Vol 189-193 ◽  
pp. 2434-2437
Author(s):  
Lei Chen
Keyword(s):  
Finite Element ◽  
Deep Drawing ◽  
Element Model ◽  
Expansion Ratio ◽  
Thickness Variation ◽  
Ratio Analysis ◽  
Drawing Process ◽  
Forming Process ◽  
Deep Drawing Process ◽  
Maximum Thickness

In deep drawing process, the experimental approach to obtain proper die-face design is not only expensive, but also requires much time and effort. Numerical simulation of the die-face design using expansion ratio analysis (ERA) can provide an avenue for lowering the cost and increasing the speed of the design process. A finite-element model of four-node quadrangle element is developed based on static implicit method using the Finite Element Code Marc. By the use of the model, the die-face design of oil pan deep drawing process is simulated. The relationship between the ERA and the maximum thickness variation is obtained. The smaller the ERA, the smaller the maximum thickness variation can be acquired. The mission success rate of the forming process increases, too. All the simulation results show reasonable agreement with the experiment.

Influence of the Tool Clearances on the Dimensional Accuracy of Mini Drawn Parts

2014 ◽  
Vol 1036 ◽  
pp. 309-313
Author(s):  
Gheorghe Brabie ◽  
Bogdan Chirita ◽  
Elena Costache ◽  
Robert Stefanut Teaca
Keyword(s):  
Process Parameters ◽  
Deep Drawing ◽  
Dimensional Accuracy ◽  
Thin Sheets ◽  
Forming Process ◽  
Cold Forming ◽  
Small Thickness ◽  
Theoretical Profile ◽  
Small Parts

The mini deep drawing is a cold forming process applied in order to realize small parts having dimensions smaller than 20 mm. In the case of such process the small thickness of sheet and the small dimensions of parts are the most important factors that influence the process parameters and can affect the accuracy and quality of the produced mini - parts. A proper clearance between the working tools components is also a very important factor that can permit to obtain mini drawn parts in accordance with their theoretical profile. The present paper analyses the results of investigations made by experiment and simulation concerning the influence of tool clearances values on the accuracy of dimensions in the case of mini scale cylindrical drawn cups made from thin sheets. The deviations from the cups theoretical profile (wall inclination, variation of part diameter) that can occur during deep drawing of such sheets were especially analyzed in the paper.

Analysis of Numerical Simulation and Engineering Examples of Drawing-Bulging Forming Parts

2012 ◽  
Vol 246-247 ◽  
pp. 365-369
Author(s):  
Kang Chen ◽  
Cheng Yun Peng ◽  
Hui Liu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Convex Hull ◽  
Deep Drawing ◽  
Material Flow ◽  
Theoretical Calculations ◽  
Case Material ◽  
Forming Process ◽  
Process Plan ◽  
Finite Element Numerical Simulation

Drawing-bulging forming is a forming method both deep drawing forming and bulge forming, it has been studied in a centrifuge cover for instance. The forming processes of the centrifuge cover have been analyzed, and the convex hull forming of the forming processes is a typical drawing-bulging forming. The convex hull forming has been analyzed by the theoretical calculations and finite element numerical simulation. The results shows that the convex hull forming should be earlier than the box-shaped forming, in this case, material flow is more conducive to control. In order to avoid the rupture in the forming process of the convex hull, the convex hull forming can be divided into two steps to complete, it can reduce inward deformation resistance of the external metal, and increase the composition of the deep drawing in the drawing-bulging forming, and ease the thinning of the convex hull of the corresponding location. Finally, the reasonable process plan of the workpiece was determined.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

Grain Size Modification by Micro Rotary Swaging

2015 ◽  
Vol 651-653 ◽  
pp. 627-632 ◽  
Author(s):  
Svetlana Ishkina ◽  
Bernd Kuhfuss ◽  
Christian Schenck
Keyword(s):  
Grain Size ◽  
Longitudinal Section ◽  
Forming Process ◽  
Boundary Area ◽  
Cold Forming ◽  
Flat Surfaces ◽  
Rotary Swaging ◽  
2D Simulation ◽  
Physical Tests ◽  
Formed Part

Rotary swaging is a well established cold forming process e.g. in the automotive industry. In order to modify the material properties by swaging systematically, a new process of swaging with asymmetrical strokes of the forming dies is investigated. The newly developed tools feature flat surfaces and do not represent the geometry of the formed part as in conventional swaging. Numerical simulation and physical tests are carried out with special regard to the resulting geometry, mechanical properties and the microstructure. During these tests copper wires with diameter d0=1 mm are formed. Regarding the microstructure in the longitudinal section of formed specimens, elongation of grains in the central part and grain size reduction in the boundary area are observed. Furthermore, this approach opens up new possibilities to configure the geometry of wires. 2D-simulation is applied and discussed in the paper to investigate change of the processed geometry (cross-section) and shear strain distribution during the rotary swaging process.

Characteristics of Rotary Draw-Bent Tubes for the Hydroforming

2011 ◽  
Vol 213 ◽  
pp. 320-324
Author(s):  
Byeong Don Joo ◽  
Jeong Hwan Jang ◽  
Hyun Jong Lee ◽  
Young Hoon Moon
Keyword(s):  
Cross Section ◽  
Structural Strength ◽  
Dimensional Accuracy ◽  
Thickness Variation ◽  
Important Process ◽  
Rotary Draw Bending ◽  
Higher Dimensional ◽  
Bending Process ◽  
Geometric Size ◽  
Draw Bending

Hydroformed parts have higher dimensional accuracy, structural strength, and dimensional repeatability. The pre-bending process is an important process for the successful hydroforming in the case where the perimeter of the blank is nearly the same as that of final product. At initial pre-bending stage, the variations of wall thickness and cross-section have effects on the accuracy of final products and quality. Because of a relatively excellent productive velocity, geometric size precision and reliance of product qualities, rotary draw bending is widely used. This study shows the bendability such as cross-section ovality, springback ratio and thickness variation in the various conditions of materials.

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