Deformation Mechanisms of Ti6Al4V Sheet Material during the Incremental Sheet Forming with Laser Heating

2013 ◽  
Vol 549 ◽  
pp. 372-380 ◽  
Author(s):  
Linda Mosecker ◽  
Alexander Göttmann ◽  
Alireza Saeed-Akbari ◽  
Wolfgang Bleck ◽  
Markus Bambach ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Microstructural Evolution ◽  
Elevated Temperatures ◽  
Sheet Material ◽  
Sheet Thickness ◽  
High Strength ◽  
Local Strain ◽  
Deformation Mechanisms ◽  
Dislocation Glide ◽  
Sheet Metal Parts

ncremental sheet metal forming (ISF) is a suitable process for the production of small batch sizes. Due to the minor tooling effort and low forming forces, ISF enables the production of large components with inexpensive and light machine set-ups. Hence, ISF is an interesting manufacturing technique for aeronautical applications. Sheet metal parts in aircrafts are often made of titanium and its alloys like the high strength alloy Ti Grade5 (Ti6Al4V). The characteristic low formability of Ti6Al4V at room temperature requires forming operations on this material to be carried out at the elevated temperatures. The interaction of heating and deformation cycles results in a microstructure evolution, which is believed to have a high impact on formability and product quality. In the present work, the temperature-dependent microstructural evolution of the as-deformed parts was investigated. Longitudinal pockets with different depths were formed using a laser-assisted ISF process. The microstructural evolution and hardening of the material were analyzed with respect to the local strain in different forming depths and pocket zones. The formability of the material together with the deformation depth and the sheet thickness-reduction were found to be strongly dependent on the applied process temperatures and the activated deformation mechanisms like dislocation glide and dynamic recrystallization.

Methodology to Produce Locally Heat-Treated EN AW-5182 Aluminum Alloy Sheet Metal Parts

2012 ◽  
Vol 504-506 ◽  
pp. 113-118 ◽  
Author(s):  
Andreas Magnus Sulzberger ◽  
Marion Merklein ◽  
Wolfgang Staufner ◽  
Daniel Wortberg
Keyword(s):  
Sheet Metal ◽  
Material Flow ◽  
Sheet Thickness ◽  
Alloy Sheet ◽  
Second Step ◽  
Material Failure ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Material Recovery ◽  
Heat Treated

Compared to steel, aluminum has a reduced formability. The consequence is that the drawability of aluminum needs to be extended. This can be achieved by a material recovery that takes place near the zones in which a material failure is initiated during deep drawing. In the considered process, first the aluminum component will be preformed to a specific stress state. In the second step, it will be partial heat treated, before the component is getting finished. Based on the selective intermediate introduction of heat, the material flow of the pre-drawn part is influenced in such a manner that the most highly stressed zones are subjected to further reduction in sheet thickness. This is possible by sacrificing material out of zones near the crack. These areas are referred to below as “sacrificial zones”. They depend on the position of the critical region as a result of the material pre-strain. In these regions, the temperature can be varied. This paper focuses on the development of a methodology to determine a layout of intermediate heat treatment of preformed aluminum sheet metal components. In order to determine such a layout, a principal part must be designed on which the methodology can be reviewed.

Influence of the Sheet Manufacturing Process on the Forming Limit Behaviour of Twin-Roll Cast, Rolled and Heat-Treated AZ31

2017 ◽  
Vol 746 ◽  
pp. 154-160 ◽  
Author(s):  
Thorsten Henseler ◽  
Madlen Ullmann ◽  
Rudolf Kawalla ◽  
Franz Berge
Keyword(s):  
Sheet Metal ◽  
Elevated Temperatures ◽  
Lightweight Design ◽  
Sheet Thickness ◽  
Forming Limit ◽  
Specific Strength ◽  
Heat Treated ◽  
Limit Behaviour ◽  
Twin Roll Cast ◽  
Twin Roll

In the age of lightweight design, magnesium alloys play an increasing role in weight reduction of transport vehicles. The specific strength compared to aluminium alloys and steel grades is superior, giving the material great potential in lightweight application. The automobile and aeronautic industry use sheet metals with minimum thicknesses, making research in this field very important. Successful sheet metal forming depends on various process parameters and material characteristics. Thus, the influence of sheet thickness on the forming limit behaviour of twin-roll cast, rolled and heat-treated AZ31 was investigated. Nakajima tests were performed on a hydraulic sheet metal testing device at elevated temperatures with various sheet thicknesses from 0.6 mm to 2.0 mm. The results show an increase in formability with rising temperatures for all sheets. Furthermore, changes in formability among the sheet thicknesses were linked to their divergent microstructures, which result from the different sheet manufacturing parameters.

Experimental Study on Galling Behavior of Advanced High Strength Steel in Sheet Metal Forming

2012 ◽  
Vol 502 ◽  
pp. 36-40
Author(s):  
Ying Ke Hou ◽  
Shu Hui Li ◽  
Yi Xi Zhao ◽  
Zhong Qi Yu
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Sheet Material ◽  
High Strength Steels ◽  
High Strength ◽  
Forming Process ◽  
Advanced High Strength Steels ◽  
Sheet Materials ◽  
Materials Used

Galling is a known failure mechanism in many sheet metal forming processes. It limits the lifetime of tools and the quality of the products is affected. In this study, U-channel stamping experiments are performed to investigate the galling behavior of the advanced high strength steels in sheet metal forming . The sheet materials used in the tests are DP590 and DP780. In addition to the DP steels, the mild steel B170P1 is tested as a reference material in this study. Experimental results indicate that galling problem becomes severe in the forming process and the galling tendency can be divided into three different stages. The results also show that sheet material and tool hardness have crucial effects on galling performance in the forming of advanced high strength steels. In this study, DP780 results in the most heaviest galling among the three types of sheet materials. Galling performance are improved with increased hardness of the forming tool.

Sheet Metal Forming - A New Kind of Forge for the Future

2007 ◽  
Vol 344 ◽  
pp. 9-20 ◽  
Author(s):  
Manfred Geiger ◽  
Marion Merklein
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Elevated Temperatures ◽  
High Strength ◽  
Light Weight ◽  
Influencing Parameters ◽  
General Possibility ◽  
Industrial Relevance ◽  
Weight Structures

Within the last years in sheet metal forming a trend towards forming at elevated temperatures as well as temperature assisted forming technologies can be observed. This development is caused by the increasing need on light and high strength materials in order to fulfill the demands of light weight structures. The decision which kind of temperature assistance is the most useful in order to improve the formability of the material depends on a hugh number of process influencing parameters, like e.g. the material itself, the geometry of the component, the number of forming operations etc.. In this paper the general possibility to separate different temperature assisted forming processes with regard to the used materials will be introduced. The different forming procedures will be explained and discussed. Examples with an industrial relevance are shown.

scholarly journals ТЕХНОЛОГІЧНІ АСПЕКТИ ЗАБЕЗПЕЧЕННЯ ЯКОСТІ ДЕТАЛЕЙ ПРИ ПНЕВМОУДАРНОМУ ШТАМПУВАННІ ВИРУБУВАННЯМ-ПРОБИВАННЯМ

2020 ◽  
pp. 137-150
Author(s):  
В. В. Кухар ◽  
Є. А. Фролов ◽  
С. Г. Ясько
Keyword(s):  
Elastic Medium ◽  
Sheet Material ◽  
Experimental Studies ◽  
High Strength ◽  
Technological Capabilities ◽  
Sheet Metal Parts ◽  
Pneumatic Impact ◽  
Cutting Surface ◽  
Similar Character ◽  
Cutting Processes

The paper considers the issues related with technological capabilities and features of the process of cutting-punching of sheet-metal parts with an elastic medium of pneumatic impact stamping, taking into account the indicators of their quality and accuracy, and also suggests effective ways to improve them. One of the promising methods for producing high-precision parts, including those with a complex profile, is a shaping method based on the technology and equipment of pneumatic shock stamping with an elastic medium on the TA-1324 in-stallations. The advantages of this method are environmental cleanliness, safe operation, wide technological capabilities, mobility and versatility, low labour and energy costs. At these installations it is advisable to perform formative operations of separation (cutting-punching) and shallow shaping both as a separate operation and together with cutting-punching. As a workpiece for the study the sheet material of the following grades was used: steel 08kp, aluminium alloy AMG-M, steel 12X18H10T. The thickness varied within the range from 0.5 to 2.5 mm. Dies and copier punches were made of U8A steel, followed by heat treatment to a hardness of HRC 56-62. An analysis of the experimental studies of punching-cutting processes allows us to conclude that with an increase in the number of stamped parts, there is an increase in size deviations from their nominal values. This increase is due to the wear of operating elements (copier punches and dies). At the same time, the sizes of the copier punches are reduced, and the sizes of the matrices are increased. The absolute values of deviations do not depend on the type of operations; their values, both during cutting and punching, are almost the same in each of the samples taken. The process of pneumatic impact stamping, where a hammer with a bevelled end was used, has a similar character. The paper also proposed and tested ways to improve pneumatic impact stamping, providing cutting, punching of parts from sheet copper, aluminium alloys with a thickness of 0.3 to 3 mm and mild steel up to 3 mm thick. The roughness of the cutting surface is in the range Ra = 0.3 to 0.6 μm, and in the case of high-strength materials up to 2.5 mm thick, the roughness of the cutting surface is Ra = 0.6 to 1.0 μm, depending on the contour configuration that is cut down or punched.

Analysis of Multiple Stage Hydroforming of Sheet Metal With Intermediate Annealing

1998 ◽  
Author(s):  
Varadaraju A. Gandikota ◽  
Viswanathan Madhavan ◽  
Steven J. Hooper
Keyword(s):  
Sheet Metal ◽  
Fluid Pressure ◽  
Sheet Thickness ◽  
Aircraft Engine ◽  
Heat Treatments ◽  
Intermediate Annealing ◽  
Sheet Metal Parts ◽  
Element Simulation ◽  
Thickness Variations ◽  
Explicit Dynamic

Abstract This paper presents the development of a finite element simulation of multistage hydroforming of sheet metal parts with annealing between forming stages, implemented using the commercial explicit dynamic code LS-DYNA. In each of the hydroforming stages, the sheet is formed to the shape of the die used in that stage by the application of fluid pressure on the top surface of the sheet. At the end of each stage, the stresses in the part are relieved and changes in material properties due to various heat treatments are accommodated while maintaining the deformed geometry of the part, including sheet thickness variations. In this manner the forming of an aircraft engine nacelle inlet lip in three stages with annealing between the stages has been simulated. In addition, single stage hydroforming to the final shape and three stage forming without intermediate annealing have been simulated. The results are used to compare the effectiveness of intermediate die shapes to the effectiveness of intermediate heat treatments in extending sheet metal formability. It is found that intermediate heat treatments enhance the ability of intermediate die shapes to promote uniform deformation of the sheet.

FE Simulation of Sheet Metal Forming – State of the Art in Automotive Industry

2005 ◽  
Vol 6-8 ◽  
pp. 13-18 ◽  
Author(s):  
H.J. Haepp ◽  
M. Rohleder
Keyword(s):  
Sheet Metal ◽  
Automotive Industry ◽  
Development Process ◽  
High Strength Steels ◽  
Feasibility Studies ◽  
High Strength ◽  
Element Analysis ◽  
Early Design ◽  
Metal Parts ◽  
Sheet Metal Parts

Nowadays feasibility studies using finite element analysis are performed in very early design phases of sheet metal parts forming. Further, simulation technology is used to optimize the first forming stage. Because of the ever intensifying international competition and the increased use of high-strength steels and aluminum alloys, the absorption of springback deviations is a great challenge, especially in the automotive industry. The application of numerical computation to predict springback deviations and to create compensated die designs in early design phases of sheet metal parts forming becomes essential. At DaimlerChrysler the numerically based compensation of springback deviations during the die development process of complex car parts is achieved. However, developments to optimize and compensate dies automatically or to predict form deviations on assemblies are still necessary.

High Strength Aluminium Sheet Metal Joining by Resistance Spot Welding

2013 ◽  
Vol 765 ◽  
pp. 761-765 ◽  
Author(s):  
Rudolf Gradinger ◽  
Nikolay Sotirov ◽  
Gottfried Rettenbacher ◽  
Christoph Pangerl ◽  
Philipp Dörner ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Spot Welding ◽  
Elevated Temperatures ◽  
Stable Process ◽  
High Strength ◽  
Automotive Body ◽  
Aerospace Applications ◽  
Joining Technology ◽  
Body In White ◽  
Opening Up

Aluminium AA7075 is well known as extrusions, plate or sheet metal predominately in aerospace applications. The continuing efforts for reducing the weight but still maintaining the safety of vehicle structures are opening up the way for this alloy in automotive applications. Since this branch is very different to space as well as aircraft industries in manufacturing methods, costs and production numbers, the development of appropriate processes is necessary. After showing a high potential for deep drawing of AA7075 sheets under elevated temperatures, the joining technology options are now under investigation too. Since spot welding is very common in automotive body-in-white manufacturing, an innovative version of this process is evaluated for applicability for welding AA7075-T6 sheets to each other and to proven automotive aluminium alloys. The results of sample weldments, including mechanical static strength, micrographs, hardness, radiography and parameters for a stable process range, are presented.

Tensile Properties and Deformation Mechanisms in Two-Phase Titanium Aluminide Sheet Material

1996 ◽  
Vol 460 ◽  
Author(s):  
F. Appel ◽  
H. Clemens ◽  
W. Glatz ◽  
R. Wagner
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Tensile Properties ◽  
Deformation Behavior ◽  
Titanium Aluminide ◽  
Elevated Temperatures ◽  
Sheet Material ◽  
Deformation Mechanisms ◽  
Structural Components ◽  
Two Phase

ABSTRACTThe mechanical properties of two-phase TiAl sheets with different compositions and microstructures were investigated over the temperature range 25–1000 °C. The microprocesses of plasticity were characterized by electron microscope observations. Particular emphasis has been paid to the mechanisms governing the deformation behavior at elevated temperatures which are relevant for the fabrication and engineering applications of structural components.

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