Structure uniformity and limits of grain refinement of high purity aluminum during multi-directional forging process at room temperature

Zhu, Qingfeng; Li, Lei; Ban, Chunyan; Zhao, Zhihao; Zuo, Yubo; Chen, Jianzhong

doi:10.1016/s1003-6326(14)63192-7

Cited by 58 publications

(19 citation statements)

References 21 publications

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“…As a result, an inhomogeneous grain structure forms in bulk material [21][22][23][24]. The grain structure consists of very fine grains and coarse grains in pure Al subjected to multi-directional forging at room temperature [25,26]. Similar grain bimodalities are observed in many aluminum-based alloys [9,21,[27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 82%

The Effect of Isothermal Multi-Directional Forging on the Grain Structure, Superplasticity, and Mechanical Properties of the Conventional Al–Mg-Based Alloy

Mikhaylovskaya

Котов

Kishchik

et al. 2019

Metals

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The current study observed a grain structure evolution in the central part and periphery of the sample of an Al–Mg–Mn-based alloy during isothermal multidirectional forging (IMF) at 350 °C with a cumulative strain of 2.1–6.3 and a strain per pass of 0.7. A bimodal grain size distribution with areas of fine and coarse grains was observed after IMF and subsequent annealing. The grain structure, mechanical properties, and superplastic behavior of the samples subjected to IMF with a cumulative strain of 6.3 and the samples exposed to IMF with subsequent cold rolling were compared to the samples exposed to a simple thermo-mechanical treatment. The micro-shear bands were formed inside original grains after the first three passes. The fraction of recrystallized grains increased and the mean size decreased with an increasing cumulative strain from 2.1 to 6.3. Significant improvements of mechanical properties and superplasticity were observed due to the formation of a homogenous fine grain structure 4.8 µm in size after treatment including IMF and subsequent cold rolling.

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Section: Introductionmentioning

confidence: 82%

The Effect of Isothermal Multi-Directional Forging on the Grain Structure, Superplasticity, and Mechanical Properties of the Conventional Al–Mg-Based Alloy

Mikhaylovskaya

Котов

Kishchik

et al. 2019

Metals

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“…The MDF is a nonlinear process that can result in undesirable results due to variations in various factors before or during processing. Some of these factors include; the geometry and size of the specimen, temperature changes, plunger speed, number of passes, coefficient of friction, strain per pass, forging equipment errors, strain rate, positional errors and material properties [5][6][7]. Combining any of these uncertainties could result in production losses, product distortion (geometry or/and quality), equipment failure and sometimes accidents.…”

Section: Introductionmentioning

confidence: 99%

A multi-response optimization of the multi-directional forging process for aluminium 7075 alloy using grey-based taguchi method

et al. 2021

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The multi-directional forging process of aluminium alloy 7075 (AA 7075) is studied using Deform 3D Version 11.0 simulation software. This process results in grain refinement in the bulk material. The 7075 aluminium alloy is used widely in the aerospace and automobile industries. Thermomechanical processing affects the mechanical properties of this alloy. This study focuses on optimising process parameters that affect the multi-directional forging using simulation. In the Taguchi design of experiment, four-factors and five levels are selected. The process input parameters considered are temperature, the strain per pass, the plunger speed, and the friction coefficient (μ). From Taguchi’s orthogonal array, forging simulations are undertaken and analysed. The significance of the process output parameters: material damage, stress and strain are analysed by analysis of variance. The results show that the friction coefficient and strain per pass highly affect the stress/strain distribution. Grey relational analysis is adopted to determine the optimum process parameters. The results show that the optimal combination of parameters is: temperature (200 °C), plunger speed (5 mm/s), friction coefficient (0.6), and strain per pass (0.6). Confirmation of simulation is carried out using the optimum input parameters. From the simulation results, the grey relational grade's optimal parameters have the highest maximum effective strain of 5.57, maximum effective stress of 665 MPa, and maximum damage of 0.416 compared to other simulated results.

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“…It should be mentioned that MDF has a large potential for fabrication of ultrafine grain and even, nanostructure bulk materials which are suitable for industrial applications as compared to the other forging types; hence, it is far attractive to produce large-size metals and alloys with both great strength and good ductility. Also, the most advantages and disadvantages of the MDF process in comparison with the other SPD methods can be listed as follows 30,31 :MDF has simple die geometry, high efficiency, and great repeatability 30 .MDF can be exerted via classical forging machine with no need to particular devices.MDF can be utilized for brittle materials at room temperature due to the application of low strain rate compared to the ECAP and HPT processes 32 .Grain refinement ability is less than other SPD methods.Grain size reduction is not homogeneous through the sample. This can be compensated by pass number increment 33 .…”

Section: Introductionmentioning

confidence: 99%

“…MDF can be utilized for brittle materials at room temperature due to the application of low strain rate compared to the ECAP and HPT processes 32 .…”

Section: Introductionmentioning

confidence: 99%

Tribological and mechanical investigation of multi-directional forged nickel

Djavanroodi

Ebrahimi

Nayfeh

2019

Sci Rep

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Tailoring material properties to specific application requirements is one of the major challenges in materials engineering. Grain size is a key factor affecting physical and mechanical properties of polycrystals materials, the presented work enables insight into how the pure nickel properties are affected by application of multi-directional forging (MDF) as a well-known severe plastic deformation method. It is demonstrated that the hardness and wear rate are improved by imposing MDF process. The rate of enhancement is reduced at the higher pass numbers. It is also shown that the application of MDF process changed the mechanism of wear. Non-MDF sample’s surface shows spalling and delamination, while the dominated wear mechanism of final pass sample is peeling with a slight of adhesion. The change of wear mechanism can be associated with the reduction of friction coefficient of the deformed sample. By considering the linear correlation between the hardness and wear rate, a simple and fast procedure is proposed to estimate the wear rate of sample after the different MDF pass numbers using the corresponding hardness magnitude. Additionally, the attained microstructure of the final pass sample shows a combination of ultrafine grains and micro shear bands.

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Structure uniformity and limits of grain refinement of high purity aluminum during multi-directional forging process at room temperature

Cited by 58 publications

References 21 publications

The Effect of Isothermal Multi-Directional Forging on the Grain Structure, Superplasticity, and Mechanical Properties of the Conventional Al–Mg-Based Alloy

The Effect of Isothermal Multi-Directional Forging on the Grain Structure, Superplasticity, and Mechanical Properties of the Conventional Al–Mg-Based Alloy

A multi-response optimization of the multi-directional forging process for aluminium 7075 alloy using grey-based taguchi method

Tribological and mechanical investigation of multi-directional forged nickel

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