Hot Workability and Processing Maps of 7150 Aluminum Alloys with Zr and V Additions

The hot compressive behavior and processing maps of as-cast and extruded 7075 aluminum alloys with a similar grain size (320–350 m) were studied and compared, which allows us to directly observe the effect of segregated phases in the as-cast microstructure on the deformation behavior and hot workability of 7075 alloys. In the as-cast alloy, the compound phases segregated along the interdendritic interfaces within the interiors of original grains provided the additional sites for continuous dynamic recrystallization via the particle stimulation nucleation mechanism. As a result, the as-cast alloy exhibited higher fractions of recrystallized grains and smaller grain sizes than the extruded alloy after compression. The stress exponent values of the as-cast alloy were smaller than those of the extruded alloy. In the processing maps, the domain associated with high power dissipation efficiencies (≥35%) occurred in a wider temperature range in the as-cast alloy compared to the extruded alloy. The segregated phases that remained undissolved in the as-cast alloy after compressive deformation could be effectively eliminated during the solid solution treatment (753 K for 2 h) for T6 aging applied after hot compression. The current results suggest the possibility and advantage of omitting the extrusion step when preparing 7xxx aluminum forging or extrusion feedstocks for hot working. The proposed method can be applied to other precipitation hardenable aluminum alloys.

Download Full-text

Effect of Homogenization Treatment and Microalloying with Mn on the Microstructure and Hot Workability of AA6060 Aluminum Alloys

Journal of Materials Engineering and Performance ◽

10.1007/s11665-019-04232-7 ◽

2019 ◽

Vol 28 (8) ◽

pp. 4531-4542 ◽

Cited By ~ 2

Author(s):

Xiaoming Qian ◽

Nick Parson ◽

X.-Grant Chen

Keyword(s):

Aluminum Alloys ◽

Hot Workability ◽

Homogenization Treatment

Download Full-text

Thermal Deformation Behavior and Processing Map of Al-Mg-Er Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.913.30 ◽

2018 ◽

Vol 913 ◽

pp. 30-36

Author(s):

Ran Liu ◽

Hui Huang ◽

Ya Liu ◽

Li Rong

Keyword(s):

Flow Stress ◽

Deformation Behavior ◽

Deformation Temperature ◽

Material Model ◽

Instability Criterion ◽

Strain Rates ◽

Processing Maps ◽

Hot Workability ◽

Compression Tests ◽

Dynamic Material Model

To study the hot deformation behavior of Al-Mg-Er alloy, hot compression tests were conducted on a Gleeble-1500D thermal simulator at the temperature range of 200-500°C with the strain rates from 0.001 to 10s-1. With the increase in the deformation temperature and the decrease in strain rates, the flow stress of the Al-Mg-Er alloy decreased. Processing maps were constructed to study on hot workability characteristics. The results showed that the flow stress curves exhibited the typical dynamic recrystallization characteristics and the stress decreased with the increase of deformation temperature and the decrease of strain rate. Moreover, the processing maps were established on the basis of dynamic material model and Prasad’s instability criterion.

Download Full-text

Study on Hot Processing Maps and Flow Instability of 1235 Al Alloy Treated by Different Methods of Purification

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.1870 ◽

2011 ◽

Vol 399-401 ◽

pp. 1870-1877

Author(s):

Gao Sheng Fu ◽

Wen Duan Yan ◽

Hong Ling Chen ◽

Gui Qing Chen ◽

Chao Zeng Cheng

Keyword(s):

Strain Rate ◽

Power Dissipation ◽

Flow Instability ◽

Al Alloy ◽

Processing Maps ◽

Hot Workability ◽

Optimum Processing ◽

Lower Strain ◽

Power Dissipation Efficiency ◽

Higher Temperature

Based on the theory of processing map proposed by PRASAD, the power dissipation maps, the hot deformation instability maps and the hot processing maps of 1235 Al alloys treated by different methods of purification were built, and the effects of purification and deformation conditions at elevated-temperature on hot workability of 1235 Al alloy were analyzed. At the same time the optimum processing region and flow instability region were determined. The results show that the hot processing map of 1235 Al alloy has two instability zones in the temperature range of 300-500°C and in the strain rate ranging from 0.01s-1to 10.0s-1up to a true strain of 0.7, that is, one zone lying in the range of lower temperature and higher strain rate, the other zone in the range of higher temperature and mid strain rate. The purification effect has significant impact on hot workability of the alloy. It is found that the optimum processing region of 1235 Al alloy treated by high-efficient purification treatment is present in the range of higher temperature and lower strain rate zone, and its power dissipation efficiency is about 46%; while the optimum processing region of 1235 Al alloys treated by conventional refining treatment is present in the range of mid-temperature and lower strain rate zone or in the range of higher temperature and strain rate zone, and its power dissipation efficiency is about 23-29%. The results of observation of the deformation microstructure of 1235 Al alloy are in accordance with that of the hot processing maps of the alloy, thus showing that the calculation results of the hot processing maps are reliable.

Download Full-text

Analysis of Hot Workability of Inconel Alloys Using Processing Maps

Lecture Notes on Multidisciplinary Industrial Engineering - Advances in Computational Methods in Manufacturing ◽

10.1007/978-981-32-9072-3_10 ◽

2019 ◽

pp. 109-118 ◽

Cited By ~ 1

Author(s):

Gauri Mahalle ◽

Nitin Kotkunde ◽

Amit Kumar Gupta ◽

Swadesh Kumar Singh

Keyword(s):

Processing Maps ◽

Hot Workability ◽

Inconel Alloys

Download Full-text

Optimization of Hot Workability and Control of Microstructure in CF250 Grade Cobalt-Free Maraging Steel: An Approach Using Processing Maps

Metallography Microstructure and Analysis ◽

10.1007/s13632-017-0408-z ◽

2017 ◽

Vol 7 (1) ◽

pp. 35-47 ◽

Cited By ~ 3

Author(s):

K. V. A. Chakravarthi ◽

N. T. B. N. Koundinya ◽

S. V. S. Narayana Murty ◽

D. Sivakumar ◽

B. Nageswara Rao

Keyword(s):

Maraging Steel ◽

Processing Maps ◽

Hot Workability ◽

And Control

Download Full-text

Hot Workability Analysis of Extruded Mg-Zn-Mn-Y Magnesium Alloys with Different Phases

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1010 ◽

2012 ◽

Vol 184-185 ◽

pp. 1010-1016

Author(s):

Wei Wei He ◽

Kun Zhang ◽

Min Huang ◽

Sheng Long Dai

Keyword(s):

Strain Rate ◽

Magnesium Alloys ◽

Power Dissipation ◽

Rate Sensitivity ◽

Processing Maps ◽

Hot Workability ◽

Compression Tests ◽

Secondary Phases ◽

Forming Process ◽

Power Dissipation Efficiency

Workability, an important parameter in magnesium alloys forming process, can be evaluated by means of processing maps on the basis of dynamic materials model, constructed from experimentally generated flow stress variation with respect to strain, strain rate and temperature. To obtain the processing maps of extruded Mg-Zn-Mn-Y magnesium alloy with different secondary phases (I-phase and W-phase), hot compression tests were performed over a range of temperatures 523–673 K and strain rates 0.001~10s-1. The response of strain-rate sensitivity (m-value), power dissipation efficiency (ζ-value) and instability parameter (n-value) to temperature and strain rate were evaluated. By the superimposition of the power dissipation and the instability maps, the dynamic recrystallization (DRX) and instability zones were identified and validated through micrographs. The observations were performed in order to describe the behavior of the material under hot forming operation in terms of material damage and micro-structural modification.

Download Full-text