scholarly journals Enhancing the Mechanical Properties of AZ80 Alloy by Combining Extrusion and Three Pass Calibre Rolling

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 249 ◽  
Author(s):  
Shuaiju Meng ◽  
Hui Yu ◽  
Jun Zhou ◽  
Haisheng Han ◽  
Yongyan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Grain Structure ◽  
Processing Route ◽  
Bimodal Microstructure ◽  
Basal Texture ◽  
Micro Scale ◽  
Uniform Microstructure ◽  
Novel Processing ◽  
Az80 Alloy

An AZ80 alloy with ultra-high strength and good ductility has been successfully prepared by a novel processing route of combining extrusion and caliber rolling. The caliber rolled (CRed) AZ80 alloy has a necklace grain structure with ultrafine dynamic recrystallized (DRXed) grains formed around the micro-scale deformed grains, which is remarkably different from the uniform microstructure of as-extruded sample free from caliber rolling. In addition, both the deformed region and the DRXed part in CRed AZ80 alloy exhibit more random basal texture than that of the as-extruded sample. Furthermore, the CRed AZ80 alloy demonstrates an excellent comprehensive mechanical property with the ultimate tensile strength of 446MPa and elongation of 13%, respectively. These good mechanical properties of CRed AZ80 alloy can be attributed to the synthetic effects of necklace bimodal microstructure containing ultra-fine grains, profuse Mg17Al12 precipitates, and the modified texture.

scholarly journals Effect of Multi-Pass Caliber Rolling on Dilute Extruded Mg-Bi-Ca Alloy

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 332
Author(s):  
Shuaiju Meng ◽  
Hui Yu ◽  
Haisheng Han ◽  
Jianhang Feng ◽  
Lixin Huang ◽  
...  
Keyword(s):  
Grain Structure ◽  
High Yield ◽  
Processing Route ◽  
Basal Texture ◽  
High Yield Strength ◽  
Uniform Microstructure ◽  
Significant Strength ◽  
Elongation To Failure ◽  
Novel Processing ◽  
Strength Improvement

A Mg-1.32Bi-0.72Ca (BX11) alloy having bimodal grain structure was successfully prepared by a novel processing route of combining extrusion and three-pass caliber rolling. The first extruded and then caliber-rolled (E-CRed) alloy demonstrates a necklace-like grain structure with ultrafine grains formed around the microscale deformed grains, which is remarkably different from the uniform microstructure of the as-extruded alloy. In addition, the E-CRed BX11 alloy exhibits strong basal texture which is mainly original from the microscale deformed grains. Furthermore, the E-CRed BX11 alloy demonstrates excellent comprehensive mechanical properties, with an ultra-high yield strength of 351 MPa and a good elongation to failure of 13.2%. The significant strength improvement can be mainly attributed to the significant grain refinement and much stronger basal texture compared with the as-extruded sample.

scholarly journals A New Ultra-High-Strength AB83 Alloy by Combining Extrusion and Caliber Rolling

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 709
Author(s):  
Shuaiju Meng ◽  
Lishan Dong ◽  
Hui Yu ◽  
Lixin Huang ◽  
Haisheng Han ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Strength ◽  
Tensile Yield Strength ◽  
Bimodal Microstructure ◽  
Combined Effects ◽  
Basal Texture ◽  
Bimodal Structure ◽  
The Matrix ◽  
Superior Mechanical Properties

An exceptionally high-strength rare-earth-free Mg–8Al–3Bi (AB83) alloy was successfully fabricated via extrusion and caliber rolling. After three-pass caliber rolling, the homogenous microstructure of the as-extruded AB83 alloy was changed to a necklace-like bimodal structure consisting of ultra-fine dynamic recrystallized (DRXed) grains and microscale deformed grains. Additionally, both Mg17Al12 and Mg3Bi2 nanoprecipitates, undissolved microscale Mg17Al12, and Mg3Bi2 particles were dispersed in the matrix of caliber-rolled (CRed) AB83 alloy. The CRed AB83 sample demonstrated a slightly weakened basal texture, compared with that of the as-extruded sample. Consequently, CRed AB83 showed a tensile yield strength of 398 MPa, an ultimate tensile strength of 429 MPa, and an elongation of 11.8%. The superior mechanical properties of the caliber-rolled alloy were mainly originated from the combined effects of the necklace-like bimodal microstructure containing ultra-fine DRXed grains, the homogeneously distributed nanoprecipitates and microscale particles, as well as the slightly modified basal texture.

scholarly journals Effect of Ce Addition on Modifying the Microstructure and Achieving a High Elongation with a Relatively High Strength of As-Extruded AZ80 Magnesium Alloy

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 76 ◽  
Author(s):  
Zheng Wang ◽  
Jin-Guo Wang ◽  
Ze-Yu Chen ◽  
Min Zha ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
High Strength ◽  
Tensile Tests ◽  
Area Fraction ◽  
Schmid Factor ◽  
High Elongation ◽  
Az80 Alloy ◽  
Ce Content

Forming magnesium alloys with rare earth elements (La, Gd, Nd, Y, Ce) is a routine method for modifying their microstructure and properties. In the present work, the effect of Ce addition on the microstructure evolution and the mechanical properties of as-extruded Mg-8Al-0.5Zn (AZ80) alloy was investigated. All of the extruded AZ80-xCe (x = 0, 0.2, 0.8 and 1.4 wt %) alloys exhibited equiaxed grains formed by fully dynamic recrystallization, and the grain size of the extruded AZ80 alloy was remarkably reduced by ~56.7% with the addition of 1.4 wt % Ce. Furthermore, the bulk-shaped Al4Ce phase formed when Ce was first added, with the Ce content rising to 0.8 wt % or higher, and Al4Ce particles in both the nano- and micron sizees were well distributed in the primary α-Mg matrix. The area fraction of the Al4Ce particles expanded with increasing Ce content, providing more nuclei for dynamic recrystallization, which could contribute to the grain refinement. The results of the tensile tests in this study showed that Ce addition effectively improved the room temperature formability of the as-extruded AZ80 alloy, without sacrificing strength. The significantly improved mechanical properties were ascribed to excellent grain refinement, weakened texture strength, an increased Schmid factor, and a reduced area fraction of low-angle grain boundaries, all resulting from Ce addition to the as-extruded AZ80 alloy. The contribution of the nano-Al4Ce precipitates on improving the mechanical properties was also discussed in this paper.

Effect of Processing Route on Mechanical Behavior of C-Mn Multiphase High Strength Cold Rolled Steel

2007 ◽  
Vol 539-543 ◽  
pp. 4375-4380
Author(s):  
Dagoberto Brandão Santos ◽  
Élida G. Neves ◽  
Elena V. Pereloma
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Quantitative Relationship ◽  
High Strength ◽  
Microstructural Characterization ◽  
Processing Route ◽  
Accelerated Cooling ◽  
Microstructural Parameters ◽  
Transmission Electron

The multiphase steels have complex microstructures containing polygonal ferrite, martensite, bainite, carbide and a small amount of retained austenite. This microstructure provides these steels with a high mechanical strength and good ductility. Different thermal cycles were simulated in the laboratory in order to create the microstructures with improved mechanical properties. The samples were heated to various annealing temperatures (740, 760 or 780°C), held for 300 s, and then quickly cooled to 600 or 500°C, where they were soaked for another 300 s and then submitted to the accelerated cooling process, with the rates in the range of 12-30°C/s. The microstructure was examined at the end of each processing route. The mechanical behavior evaluation was made by microhardness testing. The microstructural characterization involved optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). The use of multiple regression analysis allowed the establishment of quantitative relationship between the microstructural parameters, cooling rates and mechanical properties of the steel.

Effect of High Strain-Rate Thermomechanical Processing on Microstructure and Mechanical Properties of Ti-10V-2Fe-3Al Alloy

2013 ◽  
Vol 845 ◽  
pp. 96-100 ◽  
Author(s):  
Piotr Skubisz ◽  
Marek Packo ◽  
Katarzyna Mordalska ◽  
Tadeusz Skowronek
Keyword(s):  
Mechanical Properties ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Thermomechanical Processing ◽  
Hot Forging ◽  
High Strength ◽  
Processing Route ◽  
Microstructure And Mechanical Properties ◽  
Processed Material

Results of beta forging of titanium alloy Ti-10V-2Fe-3Al and subsequent thermal treatment are presented, with analysis of the effect of the processing route on the final mechanical properties, correlated with microstructure of thermomechanically processed material. Investigation of response to high strain-rate hot-forging of microstructure and mechanical properties is focused on the effect of the strengthening mechanisms in the material after two common manners of deformation typical of that alloy. The effect of deformation conditions on final microstructure and mechanical properties was analyzed in three crucial stages of thermomechanical processing, e.i. after deformation, quenching and aging. In result, conclusions were formulated as for processing conditions promoting high strength and/or ductility.

Consolidation and Mechanical Properties of Mechanically Alloyed Al-Mg Powders

2008 ◽  
Vol 1128 ◽  
Author(s):  
Mira Sakaliyska ◽  
Sergio Scudino ◽  
Hoang Viet Nguyen ◽  
Kumar Babu Surreddi ◽  
Birgit Bartusch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Nanocrystalline Structure ◽  
Hot Extrusion ◽  
High Strength ◽  
Processing Route ◽  
Compression Tests ◽  
Mechanically Alloyed ◽  
Different Temperatures ◽  
Microstructure Density

AbstractNanostructured Al-Mg bulk samples with compositions in the range of 10 – 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al90Mg10 and Al80Mg20 were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al90Mg10 specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al60Mg40 powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.

State-of-Art High Strength Steel Sheets for the Automotive Application

2007 ◽  
Vol 539-543 ◽  
pp. 4369-4374 ◽  
Author(s):  
Toshiaki Urabe ◽  
Fusato Kitano ◽  
Takeshi Fujita ◽  
Yuji Yamasaki ◽  
Yoshihiro Hosoya
Keyword(s):  
Mechanical Properties ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Grain Structure ◽  
Solid Solution Hardening ◽  
Automotive Application ◽  
Continuous Annealing ◽  
Low Carbon ◽  
Body In White

New type of IF cold-rolled high strength steels (HSSs) with the strength level of 390 and 440MPa have been developed under the chemistry of the extra-low carbon steel containing around 60ppm C with an intentional addition of niobium by hybridizing the precipitation hardening with niobium carbides and the supplemental solid-solution hardening. In this steel, Precipitation Free Zone (PFZ) nearby recrystallized grain boundaries forms during continuous annealing. This structure leads to unique mechanical properties such as lower yielding and superior anti-secondary-work embrittlement under fine grain structure strictly required for the exposed panels in Body-in-White. Principles of the unique mechanical properties of the steel are introduced related with the formation of PFZ during annealing, and the results of further approach to improve them as the state-of-the-art product, which is widely used for the exposed panels in Body in White, are introduced in the paper.

Equal Channel Angular Pressing of Al Alloy AA2219

2009 ◽  
Vol 67 ◽  
pp. 53-58
Author(s):  
V. Anil Kumar ◽  
M.K. Karthikeyan ◽  
Rohit Kumar Gupta ◽  
P. Ramkumar ◽  
P.P. Sinha
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
High Strength ◽  
Dark Field ◽  
Grain Structure ◽  
Al Alloy ◽  
Angular Pressing

Severe plastic deformation processes (SPD) are gaining importance as advanced materials processing techniques and hold immense potential in obtaining ultra fine-grained high strength materials. Among the SPD techniques, Equal channel angular pressing (ECAP) has its own merits to produce materials with ultra fine grains in bulk with better mechanical properties. The material deforms with high level of plastic strain inside the channel resulting in grain refinement of the output material with improvement in mechanical properties. A very viable die configuration was conceptualized and die was made with 1200 channel angle. Processing of 25 mm dia. of Al alloy AA2219 at room temperature was successfully carried out and grain refinement was observed. The mechanism of grain refinement has been studied using optical and transmission electron microscopy (TEM). It was observed that low energy dislocation structure (LEDS) forms concurrently with sub-grain structure due to dislocation rearrangements, which provide stability to the evolving sub-grain structure. Dislocation mobility is hindered by the presence of precipitates and / or intermetallic dispersoids present in the matrix and results in presence of dislocations in grain interiors. The pile up of dislocations at intermetallic dispersoids was confirmed from the dark field TEM micrographs. Present paper describes the experimental procedure and followed to attain severe plastic deformation through ECAP. Increase in hardness as well as refinement in the grain size after 5-passes have been discussed in light of extensive optical and TEM. The mechanisms of grain refinement to achieve nano-grained structure and strengthening accrued from the grain refinement through ECAP has been discussed.

Effect of Initial Texture on Rollability of Mg-3Al-1Zn Alloy Sheet

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Q. Dai ◽  
W. Lan ◽  
X. Chen
Keyword(s):  
Microstructural Analysis ◽  
Alloy Sheet ◽  
Grain Structure ◽  
Basal Texture ◽  
Hexagonal Close Packed ◽  
Uniform Microstructure ◽  
Az31 Mg Alloy ◽  
Edge Cracks ◽  
Initial Texture ◽  
Anisotropic Deformation

The influence of initial texture on rollability is investigated using cuneal AZ31 Mg alloy sheets. Upon large thickness reduction, the sheet with initial basal texture has many edge cracks, whereas the sheet is crack-free if its normal direction is orthogonal to c-axis of hexagonal close packed (HCP) lattice. Microstructural analysis shows that the former one has heterogeneous grain structure owing to grain-boundary-related recrystallization, and by contrast the later one has a more uniform microstructure for the twin-related recrystallization. The initial nonbasal texture can lead to excellent rollability and anisotropic deformation, based on which a new iterative approach of rolling is proposed, which may achieve large reduction in few passes.

scholarly journals Multimodal Microstructure and Mechanical Properties of AZ91 Mg Alloy Prepared by Equal Channel Angular Pressing plus Aging

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 763 ◽  
Author(s):  
Zhenquan Yang ◽  
Aibin Ma ◽  
Huan Liu ◽  
Jiapeng Sun ◽  
Dan Song ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Magnesium Alloys ◽  
High Strength ◽  
Cost Effective ◽  
Back Stress ◽  
Grain Structure ◽  
Mg Alloy ◽  
Precipitation Strengthening ◽  
Processing Route ◽  
Good Ductility

Developing cost-effective magnesium alloys with high strength and good ductility is a long-standing challenge for lightweight metals. Here we present a multimodal grain structured AZ91 Mg alloy with both high strength and good ductility, prepared through a combined processing route of low-pass ECAP with short-time aging. This multimodal grain structure consisted of coarse grains and fine grains modified by heterogeneous precipitates, which resulted from incomplete dynamic recrystallization. This novel microstructure manifested in both superior high strength (tensile strength of 360 MPa) and good ductility (elongation of 21.2%). The high strength was mainly attributed to the synergistic effect of grain refinement, back-stress strengthening, and precipitation strengthening. The favorable ductility, meanwhile, was ascribed to the grain refinement and multimodal grain structure. We believe that our microstructure control strategy could be applicable to magnesium alloys which exhibit obvious precipitation strengthening potential.

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