Experimental Investigation on the Formability of 7075 Al – Alloy Sheet in Superplastic Forming Technique

2012 ◽  
Vol 622-623 ◽  
pp. 442-446 ◽  
Author(s):  
G. Kumaresan ◽  
K. Kalaichelvan
Keyword(s):  
Sheet Thickness ◽  
Superplastic Forming ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Strain Rates ◽  
Superplastic Behavior ◽  
Variable Parameters ◽  
Complex Shapes ◽  
Al 7075 ◽  
Temperature Ranges

Superplastic behavior of certain metals and alloys having very fine grains, very large tensile elongations are obtained within certain temperature ranges at low strain rates. These alloys can be formed into complex shapes by superplastic forming, a process that employs common metalworking techniques. This paper aims to study the formability characteristic for aluminium material (Al 7075) by considering variable parameters such as sheet thickness of 1.75 and 1.5 mm and the temperature of 520°C and 530°C.

Superplastic Forming Using Rectangular Shape Dies for Process Optimization

2018 ◽  
Vol 7 (3.6) ◽  
pp. 302
Author(s):  
Srinivas Suri ◽  
M Manzoor Hussain ◽  
Abhijit Dutta
Keyword(s):  
Complex Geometry ◽  
Sheet Material ◽  
Sheet Thickness ◽  
Superplastic Forming ◽  
Work Design ◽  
Rectangular Shape ◽  
Complex Shapes ◽  
Thickness Variations ◽  
Complex Parts ◽  
Integrated Structures

Superplastic forming is a useful tool for the fabrication of complex parts used in the aircraft and automobile industries. Superplastic forming (SPF) of sheet metal has been used to produce very complex shapes and integrated structures that are often lighter and stronger than the assemblies they replace. In the present work design and fabrication of a Superplastic forming die was taken up for producing a rectangular shape and studied the process parameters.  The sheets are made of Sn-Pb alloy in the ratio of 60-40.  The Superplastic forming operation occurs where the flow stress of the sheet material is low.  The sheet is placed in a rectangular die, which can have a simple to complex geometry, representative of the final part to be produced.  The sheet is formed into the rectangular shape using gas pressure. Various pressures were applied and parameter like sheet thickness, depth with respect to time and thickness variations of a rectangular shape.  

Experimental Analysis of Material Squeeze Factor in Two-Point Incremental Forming of AL 7075-O

2020 ◽  
Author(s):  
Ankush Bansal ◽  
Randy Cheng ◽  
Mihaela Banu ◽  
Alan Taub ◽  
Jun Ni
Keyword(s):  
Incremental Forming ◽  
Sheet Thickness ◽  
Processing Parameters ◽  
Wall Region ◽  
Forming Process ◽  
Die Surface ◽  
Complex Shapes ◽  
Al 7075 ◽  
Geometric Deviation ◽  
Metal Products

Abstract In recent years, incremental sheet forming (ISF) has shown significant potential for economically fabricating sheet metal products required in low volume. Despite its advantages of reduced forming forces and higher material formability, manufacturing complex shapes with acceptable geometric accuracy is still a challenging task. Two-point ISF (TPIF) is one variant that uses a support die to a fabricate part with intricate features. In this study, effects of material squeeze factor in the TPIF process is investigated on part accuracy and formability. Material squeeze factor is defined as the amount of sheet thickness squeezed between the forming tool and support die. It is integrated as one of the processing parameters for generating a pre-defined toolpath of the forming process. However, the effective material squeeze (SFe) obtained in experiments is either zero or significantly lower than the squeeze factor programmed (SFp) in the toolpath due to machine and tool compliance. SFp values are heuristically chosen in literature studies to maintain steady contact between the sheet and die surfaces and avoid forming through degenerated SPIF rather than the “true” TPIF process. For a 67° cone, the part kept losing contact with the die surface below SFp = 30% whereas uniform contact between sheet and die surface is achieved for SFp = 40%. Also, the geometric deviation is significantly reduced from 0.61 mm to 0.39 mm along the wall region with the higher squeeze factor. Similar results are obtained for a benchmark heart shape part.

Superplastic Forming Using Rectangular Shape Dies for Process Optimization

2018 ◽  
Vol 7 (3.6) ◽  
pp. 302
Author(s):  
Srinivas Suri ◽  
M Manzoor Hussain ◽  
Abhijit Dutta
Keyword(s):  
Complex Geometry ◽  
Sheet Material ◽  
Sheet Thickness ◽  
Superplastic Forming ◽  
Work Design ◽  
Rectangular Shape ◽  
Complex Shapes ◽  
Thickness Variations ◽  
Complex Parts ◽  
Integrated Structures

Superplastic forming is a useful tool for the fabrication of complex parts used in the aircraft and automobile industries. Superplastic forming (SPF) of sheet metal has been used to produce very complex shapes and integrated structures that are often lighter and stronger than the assemblies they replace. In the present work design and fabrication of a Superplastic forming die was taken up for producing a rectangular shape and studied the process parameters.  The sheets are made of Sn-Pb alloy in the ratio of 60-40.  The Superplastic forming operation occurs where the flow stress of the sheet material is low.  The sheet is placed in a rectangular die, which can have a simple to complex geometry, representative of the final part to be produced.  The sheet is formed into the rectangular shape using gas pressure. Various pressures were applied and parameter like sheet thickness, depth with respect to time and thickness variations of a rectangular shape. 

Texture Change of Severe Plastically Deformed Al Alloy Sheets

2010 ◽  
Vol 654-656 ◽  
pp. 1259-1262 ◽  
Author(s):  
In Soo Kim ◽  
Su Kwon Nam ◽  
Saidmurod Akramov
Keyword(s):  
Aluminum Alloy ◽  
Low Carbon Steel ◽  
Sheet Thickness ◽  
Deformation Texture ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Low Carbon ◽  
Asymmetric Rolling ◽  
Heat Treated ◽  
Texture Change

Aluminum alloy sheets have lower formability (r-value) than low carbon steel sheets in fully annealed condition. Because the texture of fully annealed aluminum alloy sheet is mainly consists of cube component {001}<100>, which shows low formability. Asymmetric rolling, one of the severe plastic deformations, gives rise to shear deformation texture through the Al sheet thickness. In this paper, the changes of texture components after the severe deformation and subsequent heat treatment in Al sheet were observed. The change of the formability after the severe plastic deformation and subsequent heat-treated Al sheets have been analyzed with the change of texture of Al alloy sheets.

Formability Analysis on Superplastic Forming of AZ91 Magnesium Alloy Sheet

2018 ◽  
Vol 385 ◽  
pp. 437-442
Author(s):  
G. Kumaresan ◽  
K. Kalaichelvan
Keyword(s):  
Magnesium Alloy ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Thermomechanical Processing ◽  
Sheet Thickness ◽  
Superplastic Forming ◽  
Alloy Sheet ◽  
Az91 Magnesium Alloy ◽  
Forming Temperature

Superplastic sheet metal forming allows the production of complex parts that are not formable under normal conditions. Superplastic sheet metal forming processes are normally based on the same common principle: the sheet metal is firmly clamped between the die halves and is blow-formed by means of gas pressure. Generally superplastic forming can only be achieved in a very narrow range of strain rates and temperature. Superplastic materials are relatively stable when deformed; this behavior is related to the observation that the flow stress of a superplastic material is very sensitive to the rate of deformation. This paper aims to study the formability characteristic of Magnesium alloy by considering variable parameters, such as the sheet thickness, forming pressure and forming temperature. The forming time of 120 minutes is constant for the formability test. Keywards: Multi dome test, superplasticity, Mg – alloy, Thermomechanical processing, Formability.

Research on Quick Superplastic Forming for Aluminium Alloy Sheet

2012 ◽  
Vol 735 ◽  
pp. 301-306 ◽  
Author(s):  
Hai Jian Liang ◽  
Xiao Wei Wu ◽  
Yong Wang ◽  
Quan Lin Jin ◽  
Zhao Li Ma ◽  
...  
Keyword(s):  
Mass Production ◽  
Simulation Experiment ◽  
Hot Stamping ◽  
Superplastic Forming ◽  
Alloy Sheet ◽  
High Rate ◽  
Hot Forming ◽  
Forming Technology ◽  
Complex Process ◽  
Better Than

This article describes the high rate superplastic forming. The high rate superplastic forming technology is a new complex process,which integrates hot stamping and superplastic forming .It has feature of rapidity of the hot stamping and character of excellent formability of the superplastic forming.We obtained the best proportion of the hot forming and the superplastic forming through simulation experiment, and formed a car’s abonnet by applying the proportion.Compared with the high rate superplastic forming,the forming quality is better than that of hot forming. and the forming time is less than that of superplastic forming. Result shows that ,the high rate superplastic forming technology can meet the requirements for mass production.

Superplastic Behavior in Ultrafine-Grained Materials Produced by Equal-Channel Angular Pressing

2008 ◽  
Vol 579 ◽  
pp. 29-40 ◽  
Author(s):  
Cheng Xu ◽  
Megumi Kawasaki ◽  
Roberto B. Figueiredo ◽  
Zhi Chao Duan ◽  
Terence G. Langdon
Keyword(s):  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Processing Method ◽  
Strain Rates ◽  
Bulk Materials ◽  
Superplastic Behavior ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials ◽  
Aluminum And Magnesium Alloys

Equal-channel angular pressing (ECAP) is a convenient processing method for refining the grain size of bulk materials to the submicrometer level. Metallic alloys processed by ECAP often exhibit excellent superplastic characteristics including superplasticity at high strain rates. This paper summarizes recent experiments designed to evaluate the occurrence of superplasticity in representative aluminum and magnesium alloys and in the Zn-22% Al eutectoid alloy.

Improvement of Mechanical Properties and Corrosion Resistance by Deformation Induced Precipitation in Al-Zn-Mg-Cu Alloy

2017 ◽  
Vol 898 ◽  
pp. 179-190 ◽  
Author(s):  
Jin Rong Zuo ◽  
Long Gang Hou ◽  
Jin Tao Shi ◽  
Hua Cui ◽  
Lin Zhong Zhuang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Thermomechanical Treatment ◽  
High Strength ◽  
Alloy Sheet ◽  
Rolling Temperature ◽  
Al Alloy ◽  
Deformation Degree ◽  
Dynamic Aging ◽  
Final Rolling Temperature ◽  
Final Rolling

A final thermomechanical treatment (FTMT) including peak aging and subsequent dynamic aging was proposed to prepare 7055 Al alloy sheets. The optimization was based on nine well-planned orthogonal experiments. Three main processing conditions in the thermomechanical treatment for obtaining the optimum synthetic properties of 7055 (i.e. preheating temperature, final rolling temperature and deformation degree) were investigated. It was shown that the final rolling temperature is the most important factor among the three parameters, and the optimum properties (yield strength: 651 MPa, ultimate tensile strength: 660 MPa) of 7055 Al alloy sheet can be gained with preheating at 140oC and 40% deformation at 170oC. With dynamic aging, grain boundary precipitates became discontinuous without much coarsening of matrix precipitates, while they were continuously distributed after T6 aging. The present optimal FTMT process can improve the intergranular / exfoliation corrosion resistance without sacrificing the strength compared to T6 tempering. The present FTMT process as a good alternative can produce high-strength Al alloy sheets with high strength and good corrosion resistance efficiently and economically.

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