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

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 33 ◽  
Author(s):  
Anastasia V. Mikhaylovskaya ◽  
Anton D. Kotov ◽  
Mikhail S. Kishchik ◽  
Alexey S. Prosviryakov ◽  
Vladimir K. Portnoy
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Shear Bands ◽  
Grain Structure ◽  
Structure Evolution ◽  
Multidirectional Forging ◽  
Fine Grain ◽  
Cumulative Strain ◽  
Mean Size ◽  
Bimodal Grain Size

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.

Effect of Multidirectional Forging and Subsequent Annealing to the Microstructure of Al-Mg-Mn Type Alloy

2020 ◽  
Vol 306 ◽  
pp. 23-32
Author(s):  
Anton D. Kotov ◽  
Mikhail Kishchik ◽  
Anastasia V. Mikhaylovskaya
Keyword(s):  
Room Temperature ◽  
Elevated Temperatures ◽  
Shear Bands ◽  
Grain Structure ◽  
Coarse Grained ◽  
Recrystallization Annealing ◽  
Type Alloy ◽  
Rich Phase ◽  
Multidirectional Forging ◽  
Fine Grain

The grain refinement is important to improve both service properties at room temperature and superplasticity at elevated temperatures. This study focuses on the effect of multidirectional forging in isothermal conditions on the microstructure of Al-Mg-Mn-type alloy. The evolution of dislocation and grain structure, and precipitates of Mn-rich phase during multidirectional forging in a temperature range of 200 to 500 °C was studied. Multidirectional forging at temperatures of 200 and 300 °C leads to the formation of shear bands in the deformed grains. The multidirectional forging at 400 and 500 °C leads to the formation of a bimodal grain structure with fine- and coarse-grained areas. Subsequent recrystallization annealing at 500 °C increases the grain size and decreases the fine grains fraction in the samples pre-deformed at 400-500°C, and, on the contrary, annealing leads to formation homogeneous and fine grain structure with size up to 6.5 μm in samples pre-deformed at 200 and 300 °C.

scholarly journals Effect of Multidirectional Forging on the Grain Structure and Mechanical Properties of the Al–Mg–Mn Alloy

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2166 ◽  
Author(s):  
Mikhail Kishchik ◽  
Anastasia Mikhaylovskaya ◽  
Anton Kotov ◽  
Ahmed Mosleh ◽  
Waheed AbuShanab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Thermomechanical Treatment ◽  
Strain Range ◽  
Grain Structure ◽  
Near Surface ◽  
Fine Grained ◽  
Multidirectional Forging ◽  
Cumulative Strain ◽  
Mean Grain Size

The effect of isothermal multidirectional forging (IMF) on the microstructure evolution of a conventional Al–Mg-based alloy was studied in the strain range of 1.5 to 6.0, and in the temperature range of 200 to 500 °C. A mean grain size in the near-surface layer decreased with increasing cumulative strain after IMF at 400 °C and 500 °C; the grain structure was inhomogeneous, and consisted of coarse and fine recrystallized grains. There was no evidence of recrystallization when the micro-shear bands were observed after IMF at 200 and 300 °C. Thermomechanical treatment, including IMF followed by 50% cold rolling and annealing at 450 °C for 30 min, produced a homogeneous equiaxed grain structure with a mean grain size of 5 µm. As a result, the fine-grained sheets exhibited a yield strength and an elongation to failure 30% higher than that of the sheets processed with simple thermomechanical treatment. The IMF technique can be successfully used to produce fine-grained materials with improved mechanical properties.

scholarly journals The Mechanical Properties of AlSi17Cu5 Cast Alloy after Overheating and Modification of CuP Master Alloy

2013 ◽  
Vol 13 (3) ◽  
pp. 68-71
Author(s):  
J. Piątkowski ◽  
M. Jabłońska
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Master Alloy ◽  
Liquid State ◽  
Alloy Composition ◽  
Cast Alloy ◽  
Primary Silicon ◽  
Grain Structure ◽  
Silicon Crystals ◽  
Fine Grain

Abstract The paper presents the results of studies on the effect of the AlSi17Cu5 alloy overheating to atemperature of 920°C and modification with phosphorus (CuP10) on the resultingmechanical (HB, Rm, R0.2) and plastic (A5 and Z) properties. It has been shown that, so-called, "timethermal treatment" (TTT) of an alloy in the liquid state, consisting inoverheating the metal to about 250°C above Tliq,holding at this temperature by 30 minutes improvesthe mechanical properties. It has also been found that overheating of alloy above Tliq.enhances the process of modification, resulting in the formation of fine-grain structure. The primary silicon crystals uniformly distributed in the eutectic and characteristics ofthe α(Al) solution supersaturated with alloying elements present in the starting alloy composition (Cu, Fe) provide not only an increase of strength at ambient temperature but also at elevated temperature (250°C).

Evolution of Microstructure and Mechanical Properties of the Thixo-Diecast 319s Alloy during Heat Treatment

2013 ◽  
Vol 765 ◽  
pp. 511-515 ◽  
Author(s):  
Da Quan Li ◽  
Xiao Kang Liang ◽  
Fu Bao Yang ◽  
You Feng He ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Alloy ◽  
Grain Structure ◽  
Precipitate Size ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Optimum Heat ◽  
Evolution Of Microstructure

The evolution of microstructure and mechanical properties during solution and ageing heat treatment process was studied in terms of a thixo-diecast impeller of 319s aluminium alloy. The cast alloy exhibited a microstructure consisting of primary uniformly distributed in α-Al globules and the eutectics. A series of heat treatment studies were performed to determine optimum heat treatment parameters, in order to achieve fine grain structure, fine silicon particles and optimal precipitate size and distribution. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the evolution of microstructure and mechanical properties. The results demonstrate that, the full T6 heat treatments are successfully applied to thixo-diecast 319s impellers. A two-step solution heat treatment is employed to prevent porosity due to overheating. The tensile properties of thixo-diecast 319s impellers were substantially enhanced after T6 heat treatment. The plate-shaped θ′ precipitates and lath-shaped Q′ precipitates are the most effective for precipitation strengthening.

Structure evolution and mechanical properties of beryllium foils subjected to cold rolling and high-vacuum annealing

2019 ◽  
Vol 750 ◽  
pp. 60-69 ◽  
Author(s):  
V.V. Mishin ◽  
P.A. Glukhov ◽  
I.A. Shishov ◽  
O.N. Stolyarov ◽  
I.A. Kasatkin
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Vacuum Annealing ◽  
High Vacuum ◽  
Structure Evolution

Novel Grain Refiner for Hypo- and Hyper-Eutectic Al-Si Alloys

2011 ◽  
Vol 690 ◽  
pp. 49-52 ◽  
Author(s):  
Magdalena Nowak ◽  
Nadendla Hari Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Al Alloys ◽  
Grain Structure ◽  
Grain Refiner ◽  
Silicon Alloys ◽  
Fine Grain ◽  
Cooling Conditions ◽  
Wide Range ◽  
Master Alloys

A novel effective grain refiner for hypo and hyper-eutectic Aluminium-Silicon alloys has been developed. The composition of the grain refiner has been optimized to produce a fine grain structure and finer eutectic. Effectiveness of grain size under various cooling conditions has also been investigated to simulate various practical casting conditions. For comparative purposes, a wide range of Al alloys have been produced with the addition of commercially available Al-5Ti-B master alloys. The results show that the addition of novel grain refiner reduces the grain size significantly. As a result of fine grains, the porosity in the solidified alloys is remarkably lower. A notable improvement in mechanical properties has also been observed.

scholarly journals Analysis of the Effect of Ultrasonic Welding on Microstructure

2018 ◽  
Vol 1 (1) ◽  
pp. 49-52
Author(s):  
Tünde Kovács ◽  
Péter Pinke
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Grain Structure ◽  
Welding Parameters ◽  
Recrystallization Process ◽  
Thin Sheets ◽  
Metal Sheets ◽  
Joining Process

Abstract Ultrasonic welding is very useful for joining thin metal sheets [1, 2]. The effect of ultrasound on microstructure is currently not well understood because the changes produced depend very much on the welding parameters and the properties of the metal being considered. Thin sheets formed by cold rolling acquire a special grain structure. During the welding process the heat produced causes recrystallization; even where heat is not applied in the joining process the recrystallization process alters the mechanical properties within the heat affected zone (HAZ). The mechanical properties of the welded samples depend on the microstructure. In this work we analyse the ultrasonic welding effect on the joint and the HAZ [3, 4].

scholarly journals Novel Drawing System Approach To Manufacture Performant Commercially Pure Aluminium Fine Wires

2021 ◽  
Author(s):  
Serafino Caruso ◽  
Giuseppina Ambrogio
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Wire Drawing ◽  
Grain Structure ◽  
Pure Aluminium ◽  
Fine Grain ◽  
Commercially Pure ◽  
Drawing System ◽  
Aluminium Wire ◽  
Evolution Of Microstructure

Abstract Due to its electro-mechanical properties, commercially pure aluminium wires have attracted the interest of automotive industry representing a functional and efficient economic solution to reduce vehicle’s weight leading to the diminishing of energy consumption and emissions in today’s society. However, to consolidate its use in this sector and in new market realities, it is necessary to increase the flexibility of the aluminium conductor wires, consenting their installation in very small spaces and with high curvatures, avoiding any failure and electrical conductivity decrease. Thus, the evolution of microstructure and service performance need to be investigated and controlled to improve the service safety. The present research shows a new approach to efficiently continuously manufacture long wires with smaller diameters and fine grains at room temperature. It is studied the strengthening effects (yield and tensile strength, plasticity, hardness), the electrical conductivity and the microstructural changes of commercial 1370 pure aluminium (99.7% Al) when traditional wire drawing process is combined with equal channel angular drawing (ECAD) technique. The results of this proposed procedure of deformation “drawing-ECAD-drawing” show an evident benefit, compared to the classic technology of production of aluminium wire, obtaining fine grain structure product with superior mechanical strength and not influenced electrical conductivity. The proposed manufacturing approach leads to fine wires enhancing the material mechanical properties by microstructural evolution (i.e. grain size reduction) avoiding the traditional post manufacturing thermal treatments requiring a high amount of energy and time and careful steps.

scholarly journals The Effect of Chemical Composition and Production Technology on the Mechanical Properties of EN AW-8006 Alloy

2021 ◽  
Vol 4 (1) ◽  
pp. 45-50
Author(s):  
Judit Pázmán ◽  
Jánosné Fehér ◽  
Viktor Gonda ◽  
Balázs Verő
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Aluminum Alloys ◽  
Reference Material ◽  
Cold Rolling ◽  
Production Technology ◽  
Iron Content ◽  
Tensile Testing ◽  
Grain Structure ◽  
Test Results

Abstract Aluminum alloys en AW-8006 with three different Fe:Mn ratios were studied. In the experiments, the temperature of the intermediate soft-annealing between the cold rolling processes and the final soft-annealing at the end of the production technology were varied. The processed samples were subjected to tensile testing and hardness measurements. The effect of chemical composition, based on the test results, showed that for samples without intermediate softening, only the increase of iron content has a significant effect on the yield stress, and the change of iron content refined the final grain structure compared to the reference material.

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