The mechanism of grain refinement and plasticity enhancement by an improved thermomechanical treatment of 7055 Al alloy

2017 ◽  
Vol 702 ◽  
pp. 42-52 ◽  
Author(s):  
Jinrong Zuo ◽  
Longgang Hou ◽  
Jintao Shi ◽  
Hua Cui ◽  
Linzhong Zhuang ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Thermomechanical Treatment ◽  
Al Alloy

scholarly journals Grain Refinement Assisted by Deformation Enhanced Precipitates through Thermomechanical Treatment of AA7055 Al Alloy

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 594 ◽  
Author(s):  
Jinrong Zuo ◽  
Longgang Hou ◽  
Xuedao Shu ◽  
Wenfei Peng ◽  
Anmin Yin ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Grain Refinement ◽  
Thermomechanical Treatment ◽  
Drag Force ◽  
High Strength ◽  
Good Alternative ◽  
Al Alloy ◽  
Intermediate Annealing ◽  
Static Recovery ◽  
Dislocation Cells

Fine-grained sheets of AA7055 Al alloy were produced by an improved double-stage rolling thermomechanical treatment (DRTMT) assisted by deformation-enhanced precipitates (DEPs). The DRTMT composed of a low temperature pre-deformation, an intermediate annealing, and a final hot rolling exhibited significantly superior tensile ductility to the conventional rolling thermomechanical treated alloy (CRTMT). Numerous fine spherical DEPs appeared after the pre-deformation. Those DEPs could exert a strong drag force on the migration of boundaries and dislocations. Dislocation cells were formed due to the drag force and dynamic recovery. These dislocation cells become polygon sub-grains by static recovery during the subsequent intermediate annealing. After the final hot deformation, with further deformation and rising temperature, low angle grain boundaries gradually stabilized and transferred to high angle grain boundaries. Due to the transformation, fine equiaxed grains were formed after DRTMT. The DRTMT alloys display superior elongation to the CRTMT alloy while maintaining high strength for grain refinement. Thus, DRTMT would be a good alternative to manufacture different heat-treatable Al alloys with fine grains efficiently.

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.

Influence of ECAP Routes on the Microstructure and Mechanical Properties of Hot Extruded 3003 Al Alloy

2007 ◽  
Vol 124-126 ◽  
pp. 1397-1400 ◽  
Author(s):  
Byoung Soo Lee ◽  
Hoon Cho
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Hot Extrusion ◽  
High Strength ◽  
Al Alloy ◽  
Deformation Structure ◽  
Ecap Processing ◽  
Fine Grained ◽  
Strain Process ◽  
Equiaxed Grains

The microstructures and mechanical properties of unidirectional deformation structured Al alloy during ECAP with various deformation routes were investigated. In order to fabricate unidirectional deformation structure for Al alloy, hot extrusion was carried out. It was found that the deformation route A in ECAP routes is the dominant route for the grain refinement and strengthening. In deformation route A, the high strength ultra-fine grained Al alloy with a grain size of ~ 200 nm was obtained due to the accumulation of consecutive strain process. In contrast, the strength of ECAP’ed Al alloy produced via deformation route C was greatly increased after one pass because the grains were strained and cancelled each pass. By contrast, the equiaxed grains were obtained in deformation route BC because the sample was rotated 90 O in the same sense in each pass. The deformation route BC was superior to the deformation route C because the deformation route BC was more favorable than the deformation route C in the accumulation of consecutive strain. It is also found that unidirectional deformation structured Al alloy via hot extrusion shows similar grain refinement tendency with equiaxed structured Al alloy during ECAP processing.

Effect of Sr on Grain Refinement of Mg–3%Al Alloy Containing Trace Fe by Carbon-Inoculation

2016 ◽  
Vol 32 (12) ◽  
pp. 1297-1302 ◽  
Author(s):  
Jun Du ◽  
Yutong Shi ◽  
Mingchuan Zhou ◽  
Wenfang Li
Keyword(s):  
Grain Refinement ◽  
Al Alloy ◽  
Carbon Inoculation

Significance of High Rate Superplasticity in Metallic Materials

1990 ◽  
Vol 196 ◽  
Author(s):  
Norio Furushiro ◽  
Shigenori Hori
Keyword(s):  
Grain Size ◽  
High Strain Rate ◽  
Strain Rate ◽  
Grain Refinement ◽  
Fine Particles ◽  
High Strain ◽  
High Rate ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Al Alloy

ABSTRACTIt has been expected that “High rate superplastic materials” will be developed for industrial applications. The Dorntype equation for high temperature deformation suggests that strain rate can be increased if the grain size is decreased. This means that grain refinement can effectively establish high strain rate superplastic materials.It is well known that a high degree of grain size refinement will result from the addition of zirconium to Al-base alloys. Powder-metallurgical processing with rapidly solidified powders is also available for the improvement of superplasticity by both the refinement of the solidified structure and the maintenance of the stable fine structure of a 7475 Al alloy during recrystallization and deformation. Therefore. P/M 7475 Al alloys containing Zr up to 0.9 wt% were selected as candidate specimens. The objective of the present paper includes the clarification of the role and the effective amount of Zr to obtain high strain rate superplastic materials. As a result, the addition of 0.3%Zr or more is effective in grain refinement of the P/M 7475 Al alloy. However, alloys containing 0.7 and 0.9 wt%Zr only show superplasticity at 793K. The optimum strain rate is shifted to a higher range with increasing Zr. The alloy of 7475 Al-0.9%Zr shows the maximum elongation of 900% at the remarkably high strain rate of 3.3×10−1 s−1.The deformation mechanism of such high stain rate superplasticity will be discussed briefly, by considering the effect of the fine particles of Zr on superplastic behavior.

Application of High-Pressure Sliding for Grain Refinement of Al and Mg Alloys

2010 ◽  
Vol 667-669 ◽  
pp. 91-96 ◽  
Author(s):  
Kiyonari Tazoe ◽  
Shuji Honda ◽  
Z. Horita
Keyword(s):  
High Pressure ◽  
Strain Rate ◽  
Grain Refinement ◽  
High Pressure Torsion ◽  
Initial Strain Rate ◽  
Mg Alloys ◽  
Initial Strain ◽  
Mg Alloy ◽  
Al Alloy ◽  
Average Grain Size

An earlier study showed that high-pressure sliding (HPS) is effective for grain refinement of pure Al in a rectangular sheet form using the principle of high-pressure torsion. In this study, the HPS is applied for grain refinement of an Al-3%Mg-0.2%Sc alloy and an AZ61 Mg alloy. HPS was conducted under a pressure of 1 GPa with sliding distances of 10 to 30 mm at room temperature for the Al alloy and at 473 K for the Mg alloy The average grain size is ~300 nm for both the Al and Mg alloys, respectively. Tensile tests showed that a superplastic elongation of ~1500% is achieved in the Al-3%Mg-0.2%Sc alloy at 573 K with an initial strain rate of 3.3x10-3 s-1 and of ~600% in the AZ61 alloy at 573 K with an initial strain rate of 1x10-3 s-1.

scholarly journals Experimental Research on Micro Structure And Mechanical Properties of Al Alloy Utilizing Sustainable Biomass As Quenching Medium

2019 ◽  
Vol 8 (11) ◽  
pp. 3695-3699
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Grain Refinement ◽  
Experimental Research ◽  
Al Alloy ◽  
Maximum Hardness ◽  
Micro Structure ◽  
Quenching Media ◽  
Cow Urine

Quenching media, time, temperature are prime factors towards the enhancement of grain refinement structure and mechanical properties in metals. The present study reports the usage of novel quenching media that is cow urine to improve the mechanical properties that is tensile strength, yield strength and hardness of Al 2585 alloy. The ingredients such as (sodium, nitrogen, sulphur, Vitamin A, B, C, D, E, minerals, manganese, iron, silicon, chlorine, magnesium etc.,) present in cow urine are homogenously which help to improve micro structure and mechanical properties of Al alloy 2585. From the study, it is revealed that maximum tensile strength and yield strength is improved and grain refinement is exhibited at 50% blend. Likewise maximum hardness at 80% blends.

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