Effect of forming conditions on frictional characteristic in cold bulk forming process of copper alloy

2021 ◽  
Vol 155 ◽  
pp. 106786
Author(s):  
Da-Wei Zhang ◽  
Guang-Can Yang ◽  
Ze-Bang Zheng ◽  
Sheng-Dun Zhao
Keyword(s):  
Copper Alloy ◽  
Forming Process ◽  
Bulk Forming ◽  
Frictional Characteristic ◽  
Cold Bulk

Joining by forming of metal–polymer sandwich composite panels

2018 ◽  
Vol 233 (10) ◽  
pp. 2089-2098 ◽  
Author(s):  
João PM Pragana ◽  
Tomás RM Contreiras ◽  
Ivo MF Bragança ◽  
Carlos MA Silva ◽  
Luis M Alves ◽  
...  
Keyword(s):  
Adhesive Bonding ◽  
Sandwich Composite ◽  
Composite Panels ◽  
Forming Process ◽  
Joining By Forming ◽  
Bulk Forming ◽  
New Concepts ◽  
Mechanical Fastening ◽  
Mortise And Tenon ◽  
Metal Polymer

This article presents new joining-by-forming processes to assemble longitudinally two metal–polymer sandwich composite panels perpendicular to one another. Process design draws from an earlier development of the authors for metal sheets to new concepts based on the combination of sheet-bulk forming with mortise-and-tenon joints. Selected examples obtained from experimentation and finite element modelling give support to the presentation. A new three-stage joining by the forming process is capable of producing mechanically locked joints with larger and stiffer flat-shaped heads than those fabricated by alternative single- or two-stage solutions. Failure in the new three-stage joining by the forming process is found to take place by cracking instead of disassembling after unbending the flat-shaped head of the joint back to its original shape. The required forming forces to produce the new metal–polymer joints are below 15 kN, allowing them to be an effective, easy-to-implement alternative to existing solutions based on adhesive bonding, welding and mechanical fastening.

Studies Concerning Numerical Prediction of Metal Fibering Obtained by Cold Bulk Forming Using Sensitivity Analysis of Tribological and Rheological Properties on a Cylindrical Crushing Process

2016 ◽  
Vol 841 ◽  
pp. 29-38
Author(s):  
Adinel Gavrus ◽  
Daniela Pintilie ◽  
Roxana Nedelcu
Keyword(s):  
Sensitivity Analysis ◽  
Constitutive Behavior ◽  
Rheological Equation ◽  
Metallic Material ◽  
High Importance ◽  
Friction Law ◽  
Bulk Forming ◽  
Cold Bulk ◽  
Abaqus Software ◽  
Softening Term

The present research paper concerns a numerical and experimental analysis of the tribologic and rheological constitutive behavior influence on prediction of metallic material forging fibering. Numerical analysis using finite element Forge® code and Abaqus software show the high importance of the friction law formulation and of the material rheological softening on the fibers morphology and on their position coordinates. Calibration and sensitivity of friction law together with the numerical sensitivity of the softening term corresponding to a Hansel-Spittel rheological equation have been studied for a cylindrical crushing test of a 16MnCr5 steel.

A Review of Liquid Forging Process

2013 ◽  
Vol 690-693 ◽  
pp. 2275-2279 ◽  
Author(s):  
Xi Na Huang ◽  
Zhi Ping Zhong ◽  
Wei Wang ◽  
Feng Jiao Li ◽  
De Hua Qiu ◽  
...  
Keyword(s):  
Liquid Metal ◽  
New Technology ◽  
Die Casting ◽  
Die Design ◽  
Forming Process ◽  
High Quality ◽  
Simulation And Optimization ◽  
Forging Process ◽  
Bulk Forming ◽  
Plastic Forming

Liquid forging is a new technology of plastic forming. It is a kind of bulk forming process with liquid metal with high-quality and efficiency and it has the characteristics of both die casting and forging. This paper will discuss the liquid forging process, die design, simulation and optimization of liquid forging [1].

Improved Tool Surfaces for Incremental Bulk Forming Processes of Sheet Metals

2012 ◽  
Vol 504-506 ◽  
pp. 975-980 ◽  
Author(s):  
Peter Sieczkarek ◽  
Lukas Kwiatkowski ◽  
A. Erman Tekkaya ◽  
Eugen Krebs ◽  
Dirk Biermann ◽  
...  
Keyword(s):  
End Milling ◽  
Plasma Nitriding ◽  
Multilayer Coating ◽  
Tool Material ◽  
High Hardness ◽  
Sheet Metals ◽  
Forming Process ◽  
Bulk Forming ◽  
Metal Sheets ◽  
Surface Patterns

Sheet-bulk metal forming is a process used to manufacture load-adapted parts with high precision. However, bulk forming of sheet metals requires high forces, and thus tools applied for the operational demand have to withstand very high contact pressures, which lead to high wear and abrasion. The usage of conventional techniques like hardening and coating in order to reinforce the surface resistance are not sufficient enough in this case. In this paper, the tool resistance is improved by applying filigree bionic structures, especially structures adapted from the Scarabaeus beetle to the tool’s surface. The structures are realized by micromilling. Despite the high hardness of the tool material, very precise patterns are machined successfully using commercially available ball-end milling cutters. The nature-adapted surface patterns are combined with techniques like plasma nitriding and PVD coating, leading to a multilayer coating system. The effect of process parameters on the resistance of the tools is analyzed experimentally and compared to a conventional, unstructured, uncoated, only plasma nitrided forming tool. Therefore, the tools are used for an incremental bulk forming process on 2 mm thick metal sheets made of aluminum. The results show that the developed methodology is feasible to reduce the process forces and to improve the durability of the tools.

Integration of Piezoceramic Tube under Prestress into a Load Carrying Structure

2014 ◽  
Vol 966-967 ◽  
pp. 651-658 ◽  
Author(s):  
Matthias Brenneis ◽  
Peter Groche
Keyword(s):  
Smart Materials ◽  
Process Development ◽  
Smart Structures ◽  
Design Parameters ◽  
Forming Process ◽  
Bulk Forming ◽  
Axial Forces ◽  
Load Carrying ◽  
Critical Components

Smart structures consisting of a load carrying structure and smart materials with actuatory and sensory capabilities feature high potential in numerous applications. However, to master the assembly conditions of smart structures, there is a need to integrate additional design parameters such as prestress of the smart material, critical loads and electric contacting as well as insulation into the process development. This paper focusses on the design of an incremental bulk forming process to integrate piezoceramic components into an aluminum tube simultaneously to the manufacturing process. Axial forces imposed on the piezoceramic are investigated numerically and experimentally to verify the design of critical components and the process control. Within this investigation, in situ measurement of the direct piezoelectric effect provides a method to validate the numerical design with regard to failure of the piezo tube and the functional properties of the overall structure.

Influence of Superimposing of Oscillation on Sheet-Bulk Metal Forming

2013 ◽  
Vol 554-557 ◽  
pp. 1484-1489 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Sven Hübner ◽  
Milan Vucetic
Keyword(s):  
Metal Forming ◽  
Dimensional Change ◽  
Extrusion Process ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Bulk Forming ◽  
State Of Stress ◽  
Metal Forming Process ◽  
Excitation Frequencies

Due to novel processes like sheet-bulk metal forming, the requirements for sheet metal forming are increased. Sheet-bulk metal forming is a new interconnected process in which the part itself is manufactured by deep drawing and the gearing will be produced with bulk forming in a combined process at room temperature. This process is characterized by a triaxial state of stress and a triaxial dimensional change with true strains up to  = 1-2 by using sheet blanks. Within the use of superimposing of oscillation on a sheet-bulk metal forming process the required forming force can be reduced and the accuracy of dimension of the part can be improved. Within this paper the influence of the superimposing of oscillation on the sheet bulk metal forming will be shown on combined ironing and external extrusion process. For the superimposing of oscillation different excitation frequencies will be analysed. Furthermore the die clearance will be varied to increase the requirements on the process. Finally the influence of the different excitation frequencies and the different die clearances will be summarized in cause and effect relationship diagram.

Determination of a Dimensionless Equation for Shear Friction Factor in Cold Forging

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
K. H. Jung ◽  
Y. T. Im
Keyword(s):  
Friction Factor ◽  
Friction Model ◽  
Cold Forging ◽  
Practical Applications ◽  
Dimensionless Equation ◽  
Bulk Forming ◽  
Highly Nonlinear ◽  
Shear Friction ◽  
Shear Friction Factor ◽  
Cold Bulk

In cold bulk forming processes, a constant shear friction model is widely used to apply friction. However, it is not easy to predict the shear friction factor since frictional behavior is highly nonlinear and is dependent upon a number of processing variables, such as the hardness of the material, lubricity, sliding velocity, surface contact conditions, and the environment, etc. This paper presents a dimensionless equation that predicts the shear friction factor at the counter punch interface mfd that was empirically determined by dimensional analysis, using the tip test results available in the literature as a function of selected process variables, such as the yield strength and initial specimen's radius of the deforming material, hardness, and surface roughness of the deforming material and the counter punch, viscosity of the lubricant, and deformation speed. To verify the determined equation, a new set of experiments were carried out for specimens made of AL7075-O. The prediction of the shear friction factor at the punch interface was also achieved by simply dividing the dimensionless equation by the x ratio defined by x = mfd/mfp, which is dependent on the hardening exponent of the deforming material based on previous studies. The predicted mfd and mfp were found to be reasonable owing to comparisons with the experimental data obtained for AL7075–O in this study. These results will be beneficial in scientifically assessing the effect of the processing parameters on the friction, individually and economically selecting the lubrication condition for cold bulk forming for practical applications.

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