scholarly journals Static Friction in Oil Lubricated Cold Forming Processes

2022 ◽  
Vol 70 (1) ◽  
Author(s):  
Wilhelm Schmidt ◽  
Philipp Heck ◽  
Christoph Gaedigk ◽  
Peter Groche
Keyword(s):  
Metal Forming ◽  
Sliding Friction ◽  
Static Friction ◽  
Test Stand ◽  
Forming Process ◽  
Cold Forming ◽  
The Past

Abstract Friction is one of the variables that have a far-reaching influence on forming processes. In the past, less attention was paid to static friction than to sliding friction in forming processes. In this paper, a test stand for the determination of static friction under load in metal forming is presented. The results are discussed using the example of an oscillating cold forming process. It could be shown that the expected influence of static friction is low in this application. Graphical abstract

scholarly journals Methods of determination of frictional resistances in sheet metal forming of car body sheets

2018 ◽  
Vol 19 (6) ◽  
pp. 756-760
Author(s):  
Tomasz Trzepieciński ◽  
Irena Nowotyńska
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Complex Function ◽  
Forming Process ◽  
The Coefficient Of Friction ◽  
Displacement Speed ◽  
Almost All ◽  
Lubrication Conditions

The friction phenomenon existed in almost all plastic working processes, in particular sheet metal forming, is a complex function of the material's properties, parameters of the forming process, surface topography of the sheet and tools, and lubrication conditions. During the stamping of the drawpieces there are zones differentiated in terms of stress and strain state, displacement speed and friction conditions. This article describes the methods for determining the value of the coefficient of friction in selected areas of sheet metal and presents the drawbacks and limitations of these methods.

scholarly journals A state of the art review of hydroforming technology

2019 ◽  
Vol 13 (5) ◽  
pp. 789-828 ◽  
Author(s):  
Colin Bell ◽  
Jonathan Corney ◽  
Nicola Zuelli ◽  
David Savings
Keyword(s):  
Metal Forming ◽  
State Of The Art ◽  
Technology Readiness ◽  
Forming Process ◽  
Research Directions ◽  
Cold Forming ◽  
Technology Readiness Level ◽  
Current State ◽  
Readiness Level ◽  
Metal Forming Process

AbstractHydroforming is a relatively new metal forming process with many advantages over traditional cold forming processes including the ability to create more complicated components with fewer operations. For certain geometries, hydroforming technology permits the creation of parts that are lighter weight, have stiffer properties, are cheaper to produce and can be manufactured from fewer blanks which produces less material waste. This paper provides a detailed survey of the hydroforming literature of both established and emerging processes in a single taxonomy. Recently reported innovations in hydroforming processes (which are incorporated in the taxonomy) are also detailed and classified in terms of “technology readiness level”. The paper concludes with a discussion on the future of hydroforming including the current state of the art techniques, the research directions, and the process advantages to make predictions about emerging hydroforming technologies.

Numerical analysis in a beverage can utilizing tube hydroforming process

2019 ◽  
Vol 28 (6) ◽  
pp. 77-83
Author(s):  
Jorge Carlos León Anaya ◽  
José Antonio Juanico Loran ◽  
Juan Carlos Cisneros Ortega
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Metal Forming ◽  
Tube Hydroforming ◽  
Forming Process ◽  
Aluminum Tube ◽  
Plastic Deformation Process ◽  
Metal Forming Process ◽  
Hydroforming Process

Numerical analysis for Tube Hydroforming (THF) was developed in this work to predict the behavior of extruded aluminum tube in a forming die for beverage can applications. THF is a metal forming process dependent of three parameters: friction between the tube and the die, internal pressure, and material properties of the tube. Strain hardening is a governing phenomenon that occurs in the plastic deformation process of metals. Hollomon’s equation offers a mathematical description of the metal behavior in the plastic zone. For a proper simulation, experimental determination of the mechanical properties of aluminum 6061-T5 were conducted and test specimens where obtained directly from the aluminum tube. Experimental data were necessary because no sufficient data of the mechanical properties of the tube were available in the literature. Numerical simulations of THF were performed, and the results were compared with analytical results for validation purposes with less than 10% of error.

Multi-Stage Cold Deep Drawing of Pure Titanium Square Cup

2015 ◽  
Vol 651-653 ◽  
pp. 1072-1077 ◽  
Author(s):  
Yasunori Harada ◽  
Minoru Ueyama
Keyword(s):  
Deep Drawing ◽  
Metal Forming ◽  
Pure Titanium ◽  
Oxide Coating ◽  
Drawing Process ◽  
Forming Process ◽  
Titanium Sheet ◽  
Cold Forming ◽  
Deep Drawing Process ◽  
Multi Stage

This paper deals with the formability of pure titanium sheet in square cup deep drawing. Pure titanium has very excellent corrosion resistance. In the metal forming process, pure titanium has very good ductility in cold forming. The normal anisotropy of pure titanium is very high. Therefore, the property is suitable to the sheet metal forming, such as deep drawing process. However, the most important problem is that the occurrence of seizure becomes remarkable in severe forming operations. Many investigations on the effect of processing conditions on the seizure of titanium were carried out. In the present study, the formability of pure titanium sheet in square cup deep drawing was investigated. For the prevention, pure titanium sheets were treated by heat oxide coating. The fresh and clean titanium is not in direct contact with the die during the forming due to the existence of the oxide layer. The material was pure titanium sheets of the JIS grade 2. The initial thickness of the blank was 0.5 mm in thickness. In the deep drawing process, the sheets were employed and a flat sheet blank is formed into a square by a punch. Forming of sheet by multi-stage deep drawing was tried. Various cups were drawn by exchanging the punch and die. The die was taper without a blankholder in the subsequent stages. The effects of the intermediate annealing and tool shape on the occurrence of seizure in square cup deep drawing were also examined. The square cups were successfully drawn by heat oxide coating. The coating of titanium sheet has sufficient ability in preventing the seizure in multi-stage deep drawing operation. The results of the present study revealed that the pure titanium square cups were successfully formed by using heat oxide coating treatment.

Preform Design in Metal Forming

1989 ◽  
Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan
Keyword(s):  
Metal Forming ◽  
Simulation Technique ◽  
Production Costs ◽  
Process Conditions ◽  
Preform Design ◽  
Forward Simulation ◽  
Forming Process ◽  
Closed Die Forging ◽  
Preform Shape

Preform design in metal forming refers to the design of an initial shape of the workpiece that, when it has undergone an associated forming process, forms the required product shape with desired property successfully without formation of defects and without excessive waste of materials. A carefully selected preform can contribute significantly to the reduction of the production costs. Preform design problems are encountered in various metal-forming processes, such as closed-die forging, shell nosing, rolling, and sheet-metal forming. Design of an optimal preform shape requires simultaneous determination of optimal process conditions. However, we are here concerned with the determination of the best preform shape under a given set of process conditions. In this chapter, a new method of “backward tracing” is introduced as an alternative approach to the solution of preform design, and the applications of this method to some specific processes are discussed. Similarly to the forward simulation technique, the backward tracing method uses the finite-element method. The forward simulation technique has been discussed in the previous chapters. Backward tracing refers to the prediction of the part configuration at any stage in a deformation process, when the final part geometry and process conditions are given. The concept is illustrated in Fig. 15.1. At time t = t0, the geometrical configuration x0 of a deforming body is represented by a point Q. The point Q is arrived at from the point P, whose configuration is given as x0–1 at t = t0–1, through the displacement field during a time-step Δt, namely, x0 = x0–1 + u0–1 Δt, where u0–1 is the velocity field at t = t0–1. Therefore, the problem is to determine u0–1, based on the information (x0) at point Q. The solution scheme is as follows: taking a loading solution u0 (forward) at Q, a first estimate of P can be made according to P(1) = x0 – u0 Δt.

Comparisons of Explicit and Implicit Finite Element Methods for Sheet Metal Forming

2014 ◽  
Vol 936 ◽  
pp. 1836-1839 ◽  
Author(s):  
Lei Chen
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Explicit Method ◽  
Forming Process ◽  
The Past ◽  
Simulation Speed ◽  
Metal Forming Process ◽  
Complex Parts

Sheet metal forming is one of the most commonly practiced fabrication processes in industry. Numerical simulations of the complex parts are possible by finite element method in the past thirty years. The most important problem of the simulation is the reliability of the model. Static implicit method (SI) and dynamic explicit method (DE) were used to simulation sheet metal forming process. It was found that simulation speed in dynamic explicit software has large effect on the simulation results. The best simulation speed is 5~10 m/s. Compared with the simulation and experimental results of thickness, draw-in and CPU time, the DE method is preferred.

Recent advances and challenges in electroplastic manufacturing processing of metals

2010 ◽  
Vol 25 (7) ◽  
pp. 1215-1224 ◽  
Author(s):  
Lei Guan ◽  
Guoyi Tang ◽  
Paul K. Chu
Keyword(s):  
Microstructure Evolution ◽  
Metal Forming ◽  
Energy Efficient ◽  
Experimental Investigations ◽  
Forming Process ◽  
Electroplastic Effect ◽  
The Past ◽  
Current State ◽  
Recent Developments ◽  
Metal Forming Process

Electroplastic manufacturing processing (EPMP) is a relatively new metal-forming process that is energy efficient, environmentally friendly, and versatile. In particular, it can be used to manufacture metals or alloys that are difficult to process by conventional manufacturing protocols. There have been significant advances in EPMP in the past decade, and this review summarizes our current state of understanding and describes recent developments in EPMP. Particular emphasis is placed on describing the mechanisms responsible for the electroplastic effect and microstructure evolution as well as major advances in EPMP of metals. Challenges facing theoretical and experimental investigations are also discussed.

Review Lecture: Hydrostatic extrusion

1969 ◽  
Vol 311 (1506) ◽  
pp. 331-347 ◽  
Keyword(s):  
Eighteenth Century ◽  
Metal Forming ◽  
Technological Development ◽  
Hot Extrusion ◽  
Forming Process ◽  
Pressure Work ◽  
The Past ◽  
Lead Pipes ◽  
Metal Forming Process ◽  
Electric Cables

The object of this lecture is to present an account of a technological development which has taken place within the last twenty years, from very simple beginnings founded largely on the pioneer high-pressure work of the late P. W. Bridgman, to a metal-forming process of considerable industrial interest. Extrusion, defined as the operation of producing rods, tubes and various complex sections by forcing a billet of metal through a suitable die with a ram, is a comparative newcomer among the industrial methods whereby metals are wrought into useful forms. It was first used to manufacture lead pipes, in the early eighteenth century, and for lead sheathing of electric cables about seventy years ago. The inventive genius of Alexander Dick, whose first patent was taken out in 1894, led to the use of hot extrusion for copper and its alloys and to the design of large machines with high throughput. Extrusion of steel has attained significance only within the past fifteen years.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

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