Hot Tensile Behavior of Superplastic and Commercial AA5083 Sheets at High Temperature and Strain Rate

2013 ◽  
Vol 554-557 ◽  
pp. 63-70 ◽  
Author(s):  
Stefania Bruschi ◽  
Andrea Ghiotti ◽  
Francesco Michieletto
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Automotive Industry ◽  
Hot Stamping ◽  
Superplastic Forming ◽  
Tensile Behavior ◽  
Tensile Behaviour ◽  
Fine Grained ◽  
Plastic Forming ◽  
Quick Plastic Forming

Since the last two decades, the automotive industry has dedicated an increasing attention to the manufacturing of sheet components made of high-resistant aluminium alloys; the superplastic AA5083 grade is currently utilized in both the conventional superplastic forming and the recently patented quick plastic forming, which assures higher productivity compared to that of superplastic forming, while the commercial AA5083 grade is rarely employed. The objective of the paper is to compare the hot tensile behaviour of commercial and fine-grained AA5083 sheets when processed at high temperature and strain rate, which are typical of hot stamping processes. The results are presented and commented in terms of flow stress, anisotropy, strain at failure, microstructural and hardness features as a function of temperature and strain rate. On the basis of the obtained results, the set of optimal forming conditions for the two grades is identified.

Tribological Testing of Graphite and Boron Nitride Lubricant Formulations for High Temperature Aluminum Sheet Forming Processes

2007 ◽  
Author(s):  
M. David Hanna ◽  
Paul E. Krajewsk ◽  
James G. Schroth
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Superplastic Forming ◽  
Solid Lubricants ◽  
Sheet Forming ◽  
Aluminum Sheet ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
Performance And Evaluation

The tribological behavior of AA5083 aluminum sheet sliding against tool steel impacts the quality of components manufactured with the elevated temperature metal forming processes such as Quick Plastic Forming (QPF), Superplastic Forming (SPF), or warm forming. This study focuses on the tribological performance and evaluation of alternative solid lubricants using a flat-on-flat tribo-tester to simulate sheet forming at high temperature applications. Improved lubricant formulations containing boron nitride with graphite additions were found to enhance lubricity while maintaining good adherence to the surface of the aluminum blank at a temperature of 450°C.

High-Temperature Forming of a Vehicle Closure Component in Fine-Grained Aluminum Alloy AA5083: Finite Element Simulations and Experiments

2010 ◽  
Vol 433 ◽  
pp. 197-209 ◽  
Author(s):  
Louis G. Hector ◽  
Paul E. Krajewski ◽  
Eric M. Taleff ◽  
Jon T. Carter
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Sheet Thickness ◽  
Alloy Sheet ◽  
Forming Process ◽  
Material Models ◽  
Fine Grained ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
Forming Defects

Fine-grained AA5083 aluminum-magnesium alloy sheet can be formed into complex closure components with the Quick Plastic Forming process at high temperature (450oC). Material models that account for both the deformation mechanisms active during forming and the effect of stress state on material response are required to accurately predict final sheet thickness profiles, the locations of potential forming defects and forming cycle time. This study compares Finite Element (FE) predictions for forming of an automobile decklid inner panel in fine-grained AA5083 using two different material models. These are: the no-threshold, two-mechanism (NTTM) model and the Zhao. The effect of sheet/die friction is evaluated with five different sheet/die friction coefficients. Comparisons of predicted sheet thickness profiles with those obtained from a formed AA5083 panel shows that the NTTM model provides the most accurate predictions.

Forming Limit Diagrams for AA5083 under SPF and QPF Conditions

2007 ◽  
Vol 551-552 ◽  
pp. 129-134 ◽  
Author(s):  
Mary Anne Kulas ◽  
Paul E. Krajewski ◽  
John R. Bradley ◽  
Eric M. Taleff
Keyword(s):  
Strain Rate ◽  
Plane Strain ◽  
Superplastic Forming ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Commercial Grade ◽  
Bulge Testing ◽  
Macroscopic Fracture ◽  
Plastic Forming ◽  
Quick Plastic Forming

Forming Limit Diagrams (FLD’s) for AA5083 aluminum sheet were established under both Superplastic Forming (SPF) and Quick Plastic Forming (QPF) conditions. SPF conditions consisted of a strain rate of 0.0001/s at 500°C, while QPF conditions consisted of a strain rate of 0.01/s at 450°C. The forming limit diagrams were generated using uniaxial tension, biaxial bulge, and plane strain bulge testing. Forming limits were defined using two criteria: (1) macroscopic fracture and (2) greater than 2% cavitation. Very little difference was observed between the plane strain limits in the SPF and QPF conditions indicating comparable formability between the two processes with a commercial grade AA5083 material.

High-Temperature Deformation of Magnesium ElektronTM 43

2012 ◽  
Vol 735 ◽  
pp. 93-100
Author(s):  
Alexander J. Carpenter ◽  
Anthony J. Barnes ◽  
Eric M. Taleff
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Superplastic Forming ◽  
Solute Drag ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Fine Grained ◽  
Boundary Sliding

Complex sheet metal components can be formed from lightweight aluminum and magnesium sheet alloys using superplastic forming technologies. Superplastic forming typically takes advantage of the high strain-rate sensitivity characteristic of grain-boundary-sliding (GBS) creep to obtain significant ductility at high temperatures. However, GBS creep requires fine-grained materials, which can be expensive and difficult to manufacture. An alternative is provided by materials that exhibit solute-drag (SD) creep, a mechanism that also produces elevated values of strain-rate sensitivity. SD creep typically operates at lower temperatures and faster strain rates than does GBS creep. Unlike GBS creep, solute-drag creep does not require a fine, stable grain size. Previous work by Boissière et al. suggested that the Mg-Y-Nd alloy, essentially WE43, deforms by SD creep at temperatures near 400°C. The present investigation examines both tensile and biaxial deformation behavior of ElektronTM 43 sheet, which has a composition similar to WE43, at temperatures ranging from 400 to 500°C. Data are presented that provide additional evidence for SD creep in Elektron 43 and demonstrate the remarkable degree of biaxial strain possible under this regime (>1000%). These results indicate an excellent potential for producing complex 3-D parts, via superplastic forming, using this particular heat-treatable Mg alloy.

Sheet Orientation Effects on the Hot Formability Limits of Lightweight Alloys

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Fadi Abu-Farha ◽  
Louis G. Hector
Keyword(s):  
Rolling Direction ◽  
Superplastic Forming ◽  
Strain Ratio ◽  
Forming Limit ◽  
Specific Strain ◽  
Plastic Forming ◽  
Lightweight Alloys ◽  
Quick Plastic Forming ◽  
The Relationship ◽  
5083 Aluminum Alloy

The formability curves of AZ31B magnesium and 5083 aluminum alloy sheets were constructed using the pneumatic stretching test at two different sets of forming conditions. The test best resembles the conditions encountered in actual hydro/pneumatic forming operations, such as the superplastic forming (SPF) and quick plastic forming (QPF) techniques. Sheet samples were deformed at (400 °C and 1 × 10−3 s−1) and (450 °C and 5 × 10−3 s−1), by free pneumatic bulging into a set of progressive elliptical die inserts. The material in each of the formed domes was forced to undergo biaxial stretching at a specific strain ratio, which is simply controlled by the geometry (aspect ratio) of the selected die insert. Material deformation was quantified using circle grid analysis (CGA), and the recorded planar strains were used to construct the forming limit curves of the two alloys. The aforementioned was carried out with the sheet oriented either along or across the direction of major strains in order to establish the relationship between the material’s rolling direction and the corresponding limiting strains. Great disparities in limiting strains were found in the two orientations for both alloys; hence, a “composite FLD” is introduced as an improved means for characterizing material formability limits.

Routes to Develop Fine-Grained Magnesium Alloys and Composites for High-Strain Rate Superplasticity

1999 ◽  
Vol 601 ◽  
Author(s):  
Toshiji Mukai ◽  
Hiroyuki Watanabe ◽  
T. G. Nieh ◽  
Kenji Higashi
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
High Strain ◽  
Thermomechanical Processing ◽  
Superplastic Forming ◽  
Fine Grained ◽  
Superplastic Properties ◽  
Rapidly Solidified

AbstractSuperplastic properties of magnesium alloys and their composites were reviewed with a special emphasis on the achievement of high strain rate superplastic forming. The role of grain size on superplastic deformation mechanisms was particularly addressed. Commercial Mg-Al-Zn alloys and a ZK60-based composite are used as model materials to illustrate the underlining principles leading to the observation of high strain rate superplasticity. In this paper, experimental results from several processing routes, including thermomechanical processing, severe plastic deformation, and extrusion of machined chips and rapidly solidified powders, are presented. High strain rate superplasticity (HSRS) is demonstrated in ZK60-based composites.

High-strain-rate superplasticity and tensile behavior of fine-grained Mg97Zn1Y2 alloys fabricated by chip/ribbon-consolidation

2019 ◽  
Vol 764 ◽  
pp. 138179 ◽  
Author(s):  
Kazuha Suzawa ◽  
Shin-ichi Inoue ◽  
Soya Nishimoto ◽  
Seigo Fuchigami ◽  
Michiaki Yamasaki ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Tensile Behavior ◽  
Fine Grained

Development of Al-Mg Alloys with Different Levels of Mn and Fe for Super-Plastic Forming

2016 ◽  
Vol 838-839 ◽  
pp. 202-207 ◽  
Author(s):  
Irina Pushkareva ◽  
Hai Ou Jin
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Strain Rate ◽  
Tensile Elongation ◽  
Super Plastic ◽  
Sheet Formability ◽  
Plastic Forming ◽  
Super Plastic Forming ◽  
High Temperature Tensile ◽  
Al Mg Alloys

New Al-Mg alloys have been developed for super-plastic forming (SPF) based on commercial AA5083/AA5086 alloys, but with an increased Mn content from 0.5 to 1.5 wt.% and a decreased impurity Fe level from 0.25 to 0.05 wt.%.The effects of Mn and Fe levels on super-plasticity have been investigated by high temperature tensile testing of cold rolled H18 sheets at 425 to 525°C with a strain rate of 2×10-3 s-1. The microstructure evolution during different processing stages, grain size and grain size stability were investigated by optical microscopy and scanning electron microscopy. Both Mn and Fe showed a similar and significant contribution to grain size control in recrystallization, but their effect on high temperature sheet formability was different. An increase in Mn level led to an improvement in high temperature tensile elongation, while an increase in Fe content reduced the sheet formability. A new alloy with 1.5 wt.% Mn and 0.05 wt.% Fe, when processed to H18 temper, was able to reach more than 400% tensile elongation at 450 - 500°C with a strain rate of 2×10-3 s-1.

Sign in / Sign up

Export Citation Format

Share Document