Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size

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

The Effect of the Erbium Content on the Microstructure and Mechanical Property of 6061 Aluminum Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.35 ◽

2017 ◽

Vol 898 ◽

pp. 35-40 ◽

Cited By ~ 2

Author(s):

Wen Jian Lv ◽

Bo Long Li ◽

Peng Qi ◽

Zuo Ren Nie

Keyword(s):

Solid Solution ◽

Grain Size ◽

Tensile Strength ◽

Aluminum Alloys ◽

Cast Alloy ◽

Solution Treatment ◽

Size Refinement ◽

Effective Grain Size ◽

Different Content ◽

Microstructure And Mechanical Property

The 6061 aluminum alloys with different content of erbium were prepared. The erbium content was optimized by measurement of grain refining effects and tensile strength. After solid solution treatment of the alloy with optimized erbium content at 505 °C ~ 595 °C for 4 h. and then ageing at –160 °C ~ 200 °C for 3 h., the grain size decreased with the content of erbium, achieving the most effective grain size refinement at the erbium content of 0.15wt.%. The tensile strength of as-cast alloy could reach up to 243 MPa at the erbium content of 0.15%. -Combined with the microstructures and mechanical properties, the erbium content of 0.15% was the optimized content, and heat treatments of ageing at 180 °C for 3 h. followed by solid solution at 565 °C for 4 h were suggested.

Download Full-text

Microstructural evolution during high-temperature tensile creep at 1,500°C of a MoSiBTiC alloy

High Temperature Materials and Processes ◽

10.1515/htmp-2020-0039 ◽

2020 ◽

Vol 39 (1) ◽

pp. 136-145 ◽

Cited By ~ 1

Author(s):

Sojiro Uemura ◽

Shiho Yamamoto Kamata ◽

Kyosuke Yoshimi ◽

Sadahiro Tsurekawa

Keyword(s):

Grain Size ◽

Grain Boundaries ◽

Microstructural Evolution ◽

Grain Boundary Sliding ◽

Primary Creep ◽

Tensile Creep ◽

Tertiary Creep ◽

Continuous Dynamic Recrystallization ◽

Continuous Dynamic ◽

Creep Regime

AbstractMicrostructural evolution in the TiC-reinforced Mo–Si–B-based alloy during tensile creep deformation at 1,500°C and 137 MPa was investigated via scanning electron microscope-backscattered electron diffraction (SEM-EBSD) observations. The creep curve of this alloy displayed no clear steady state but was dominated by the tertiary creep regime. The grain size of the Moss phase increased in the primary creep regime. However, the grain size of the Moss phase was found to remarkably decrease to <10 µm with increasing creep strain in the tertiary creep regime. The EBSD observations revealed that the refinement of the Moss phase occurred by continuous dynamic recrystallization including the transformation of low-angle grain boundaries to high-angle grain boundaries. Accordingly, the deformation of this alloy is most likely to be governed by the grain boundary sliding and the rearrangement of Moss grains such as superplasticity in the tertiary creep regime. In addition, the refinement of the Moss grains surrounding large plate-like T2 grains caused the rotation of their surfaces parallel to the loading axis and consequently the cavitation preferentially occurred at the interphases between the end of the rotated T2 grains and the Moss grains.

Download Full-text

Finite element modelling of microstructural changes during equal channel angular drawing of pure aluminium

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-06972-0 ◽

2021 ◽

Author(s):

Serafino Caruso ◽

Stano Imbrogno

Keyword(s):

Plastic Deformation ◽

Grain Size ◽

Finite Element ◽

Size Variation ◽

Fe Model ◽

Pure Aluminium ◽

Continuous Dynamic Recrystallization ◽

Research Activities ◽

Hardness Change ◽

Continuous Dynamic

AbstractGrain refinement by severe plastic deformation (SPD) techniques, as a mechanism to control microstructure (recrystallization, grain size changes,…) and mechanical properties (yield strength, ultimate tensile strength, strain, hardness variation…) of pure aluminium conductor wires, is a topic of great interest for both academic and industrial research activities. This paper presents an innovative finite element (FE) model able to describe the microstructural evolution and the continuous dynamic recrystallization (CDRX) that occur during equal channel angular drawing (ECAD) of commercial 1370 pure aluminium (99.7% Al). A user subroutine has been developed based on the continuum mechanical model and the Hall-Petch (H-P) equations to predict grain size variation and hardness change. The model is validated by comparison with the experimental results and a predictive analysis is conducted varying the channel die angles. The study provides an accurate prediction of both the thermo-mechanical and the microstructural phenomena that occur during the process characterized by large plastic deformation.

Download Full-text

Numerical Modeling of Continuous Dynamic Recrystallization in Sn-Based Solder Connection Under Cyclic Loading

10.1115/ipack2021-73319 ◽

2021 ◽

Author(s):

Marta Kuczynska ◽

Ulrich Becker ◽

Youssef Maniar ◽

Steffen Weihe

Keyword(s):

Grain Size ◽

Dynamic Recrystallization ◽

Cyclic Load ◽

Fe Simulation ◽

Operation Time ◽

Inelastic Strain ◽

Parameter Study ◽

Continuous Dynamic Recrystallization ◽

Gradual Evolution ◽

Continuous Dynamic

Abstract The reoccurring cyclic load imposed onto soldered electronic components during their operation time leads to accumulation of inelastic strains in the structure. On a microscale level, the degree of plastic deformation is determined by the formation and annihilation of dislocations, leading to continuous refinement by creation of new grain boundaries, precipitates relocation and growth. This microstructure rearrangement, triggered by an increasing amount of inelastic deformation, is defined as dynamic recrystallization. This work presents a macroscale modelling approach for the description of continuous dynamic recrystallization observed in Sn-based solder connections. The model used in this work describes kinetics of macroscopic gradual evolution of equivalent grain size, where the initial grain size is continuously refined with increasing accumulated inelastic strain until a saturation grain size is reached. The rate and distribution of dynamic recrystallization is further numerically modelled dependent on the effective accumulated inelastic strain and governing stress multiaxiality. A parameter study of the presented model and its employment in finite element (FE) simulation is further described. Finally, FE simulation of the grain size evolution is demonstrated on an example of a bulky sample under isothermal cyclic mechanical loading, as well as a BGA-like structure under tensile, shear and mixed mode cyclic load.

Download Full-text

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

Journal of Materials Engineering and Performance ◽

10.1007/s11665-015-1478-1 ◽

2015 ◽

Vol 24 (5) ◽

pp. 2126-2139 ◽

Cited By ~ 8

Author(s):

Cangji Shi ◽

X.-Grant Chen

Keyword(s):

Aluminum Alloys ◽

Processing Maps ◽

Hot Workability

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

Modelling continuous dynamic recrystallization of aluminum alloys based on the polycrystal plasticity approach

International Journal of Plasticity ◽

10.1016/j.ijplas.2020.102710 ◽

2020 ◽

Vol 131 ◽

pp. 102710 ◽

Cited By ~ 4

Author(s):

S.F. Chen ◽

D.Y. Li ◽

S.H. Zhang ◽

H.N. Han ◽

H.W. Lee ◽

...

Keyword(s):

Aluminum Alloys ◽

Dynamic Recrystallization ◽

Continuous Dynamic Recrystallization ◽

Polycrystal Plasticity ◽

Continuous Dynamic

Download Full-text

Effects of Repetitive Upsetting Extrusion on the Microstructure and Texture of GWZK124 Alloy under Different Starting Temperatures

Materials ◽

10.3390/ma12152437 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2437

Author(s):

Guanshi Zhang ◽

Zhimin Zhang ◽

Yingze Meng ◽

Zhaoming Yan ◽

Xin Che ◽

...

Keyword(s):

Grain Size ◽

Dynamic Recrystallization ◽

Grain Refinement ◽

Volume Fraction ◽

Bimodal Microstructure ◽

Continuous Dynamic Recrystallization ◽

Average Grain Size ◽

Second Phases ◽

Continuous Dynamic ◽

Weak Texture

The effects of repetitive upsetting extrusion under different starting temperatures on the microstructure and texture of GWZK124 alloy were investigated. The results clearly showed that the particles and second phases induced dynamic recrystallization (DRX), which can be explained by the particle-stimulated nucleation (PSN) mechanism. It was shown that grain refinement during repetitive upsetting extrusion (RUE) is dominated by a complicated combination of continuous dynamic recrystallization and discontinuous dynamic recrystallization. The RUEed alloys under different starting temperatures exhibited a bimodal microstructure comprising fine DRXed grains with weak texture and coarse deformed grains with strong texture. The DRXed grains could weaken the texture. As the RUE starting temperature decreased, the average grain size increased and the volume fraction of DRXed grains decreased.

Download Full-text