scholarly journals Mechanical Properties and Microstructure of the Magnesium Alloy Mg-6.8Y-2.5Zn-0.5Al Produced by Casting and Hot Rolling

2018 ◽  
Vol 918 ◽  
pp. 3-12 ◽  
Author(s):  
Kristina Neh ◽  
Madlen Ullmann ◽  
Rudolf Kawalla
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Hot Rolling ◽  
High Strength ◽  
Final Thickness ◽  
Good Thermal Stability ◽  
Specific Strength ◽  
Automotive Electronic ◽  
Rolling Temperatures

In recent years, magnesium alloys have been received much attention as important structural materials for lightweight components in automotive, electronic and space industries because of the low density, high specific strength, high damping capacities and good casting properties. Among various magnesium alloys, rare earth (RE) containing alloys are known to show high strength, excellent creep resistance, and good thermal stability. Long period stacking ordered structures (LPSO) being responsible for the improved property profile in some Mg–RE alloys. One promising system are the Mg-Y-Zn alloys, which are predominantly processed via extrusion. Only a few studies are focused on hot rolling. However, these works are confined to rolling temperatures between 350 °C and 420 °C. The present paper summarizes the development of a rolling technique including pass schedule and heat treatment for the magnesium alloy Mg-6.8Y-2.5Zn-0.5Al in as-cast condition in order to produce sheets with a final thickness of 2.5 mm. The investigations are accompanied by the characterization of the microstructure as well as the determination of the mechanical properties.

Effect of Rolling Speed on Deformability and Microstructure in Rolling of AZ31B Magnesium Alloy

2010 ◽  
Vol 89-91 ◽  
pp. 227-231 ◽  
Author(s):  
Go Hamada ◽  
Tetsuo Sakai ◽  
Hiroshi Utsunomiya
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
High Speed ◽  
Rolling Speed ◽  
Single Pass ◽  
Specific Strength ◽  
Superior Mechanical Properties ◽  
Hcp Structure ◽  
Edge Cracking

Magnesium alloys are expected to be used widely as structural materials because of their lowest density (1.8g/cm3) among all practical alloys and superior specific strength. However, magnesium alloys exhibit poor ductility due to its hcp structure and inactiveness of non-basal slip systems below 523K. Accordingly, magnesium alloy sheets had to be rolled at elevated temperature to avoid edge cracking and fracture during rolling. The present authors succeeded in single pass large draught rolling of AZ31 magnesium alloy sheets below 473K without heating rolls by rolling at the speed higher than 1000m/min. The rolled and quenched sheets had fine recrystallized microstructure and exhibited excellent mechanical properties. It was found that the high speed rolling is a promising method not only for increasing productivity but also for controlling microstructures and improving mechanical properties. If the above mentioned advantages of high speed rolling can be drawn from the rolling at the speed lower than 1000m/min, it is possible to mass-produce magnesium alloy sheets having superior mechanical properties at lower cost. In this study, we tried to determine the lower limiting rolling speed at which we can obtain advantages of high speed rolling. We revealed that the thickness could be reduced about 60% by single pass operation even at 250m/min without heating rolls. The rolled and quenched sheets had equiaxed fine recrystallized microstructure. For example, the mean grain size of 2.1m was obtained in the AZ31B sheet rolled at 250m/min at room temperature to the reduction of 60%.

scholarly journals The influence of aluminum on the formation of the hardening phase in magnesium alloys

2021 ◽  
pp. 14-18
Author(s):  
V. Shalomeev ◽  
О. Lukianenko
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Heat Resistance ◽  
Magnesium Alloys ◽  
Intermetallic Phase ◽  
High Strength ◽  
Optimal Level ◽  
Cast Metal ◽  
Positive Effect

Purpose. Study of the effect of alloying with aluminum on structure formation, mechanical properties and heat resistance of magnesium alloys Research methods. Methods of metallographic and micro X-ray spectral analysis. Determination of mechanical properties and heat resistance. Results. The regularities of the influence of alloying with aluminum on the formation of the hardening phase in magnesium alloys have been investigated. It is shown that an increase in the concentration of aluminum in  magnesium alloy promotes refinement of the macro- and microstructure of the metal (reduces the grain size and the distance between the second-order dendritic axes) and also increases the amount of intermetallic phase. The positive effect of aluminum additives on the mechanical properties and heat resistance of cast metal has been established. The optimal level of alloying with aluminum (about 7,7 %) hes been determined, which ensures a sufficient level of mechanical properties and heat resistence. Scientific novelty. Based on the regression analysis of the experimental data, empirical equations were obtained that describe the dependences of the size of macro- and micrograins on the concentration of aluminum in magnesium alloys. It is shown that the optimal aluminum content in the magnesium alloy in the amount of ~ 7,7 % provides the best combination of mechanical properties (a sufficiently high strength and the highest plasticity) and heat resistance Practical value. It has been established that alloying magnesium alloys with aluminum is promising for improving the structure and increasing the mechanical properties and heat resistance of cast metal. This effect makes it possible to significantly expand the field of application of magnesium alloys in mechanical engineering and improve the performance of various equipment.

Effect of Rolling and Annealing on the Mechanical Properties and Microstructure of AZ31 Magnesium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 379-382
Author(s):  
Guang Jie Huang ◽  
Ling Yun Wang ◽  
Guang Sheng Huang ◽  
Fu Sheng Pan ◽  
Qing Liu
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Hot Rolling ◽  
Az31 Magnesium Alloy ◽  
Final Thickness ◽  
Microstructural Investigation ◽  
Az31 Sheet ◽  
Cold Rolling And Annealing ◽  
Cold Rolled ◽  
Hot Rolled

Microstructural evolution and mechanical properties of the AZ31 magnesium alloy during rolling and annealing process were investigated. The sheet samples were prepared after different stages of the hot rolling, cold rolling and annealing processes. The hot rolling temperature was between 300-450C and the final thickness of the cold rolled sheets was 1.5mm. The cold rolled sheets were annealed at different annealing temperature (260-350C) for different time (10~120min). Tensile test was performed to investigate the mechanical properties of the samples obtained from different stages. With aid of the optical microscopy, scanning electron microscopy (SEM) techniques, the microstructure of the samples were characterized and the results were related to the mechanical properties. It was found the hot-rolled sheets exhibit higher ductility comparing with the cold-rolled sheets. The microstructural investigation showed that the microstructure of the hot-rolled samples was dominated by recrystallized equiaxed grains while the microstructure of the cold-rolled samples dominated by deformation twining. By applying annealing on the cold-rolled sheets, fine recrystallization grains were obtained and ductility of the samples was improved. The effects of the grain size and twining on mechanical properties of the AZ31 sheet were further discussed based on the experimental results.

The Study of Electrochemical Property of Organic Coating on Magnesium Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 433-436
Author(s):  
Bai Yang Lou ◽  
Yao Tang ◽  
Ke Zai Miao ◽  
Bin Xu
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Base Alloy ◽  
High Strength ◽  
Corrosion Current ◽  
Organic Coating ◽  
Open Circuit ◽  
Corrosion Property ◽  
Organic Coatings ◽  
Specific Strength

Magnesium Alloys are of low density, high specific strength and high strength, leading to much application prospect in industry and civilian use. However, the alloys are restrictedly used because of easy corrosion. In this paper, The Organic coatings on Magnesium Alloys are made. The electrochemical properties of organic coatings are researched by scanning electron microscope (SEM), stereoscopic microscope and electric-chemistry Work station. The research results show that the curves of open-circuit current to time and Tafel polarization shuffle more for the Pu and ER/PU coatings than for base alloy. With addition of the coating, the magnesium alloy has much low corrosion current density (icorr) and high polarization resistance (Rp), and then its Anti-corrosion Property is evidently improved.

Study on Partial Remelting Microstructures and Mechanical Properties of ZK60-RE Magnesium Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 279-283
Author(s):  
Wei Wei Shan ◽  
Zhi Ming Du ◽  
Shou Jing Luo
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Equal Channel Angular Extrusion ◽  
High Strength ◽  
High Quality ◽  
Partial Remelting ◽  
Semi Solid ◽  
Re Elements

ZK60-RE is a kind of high strength magnesium alloy. Here, starting materials are casting ZK60-RE magnesium alloy and ZK60-RE magnesium alloy extruded by equal channel angular extrusion (ECAE), reheating to semi-solid state and studied on their partial remelting microstructures by means of microscope. The results show that ZK60-RE magnesium alloy extruded by ECAE are much finer and lead to the formation of spheroids quite rapidly while RE elements modified casting need a little longer time. At the same time, the mechanical properties of two kinds of ZK60-RE magnesium alloys are given. To do that, we want to find better magnesium alloys with high mechanical properties and good thixotropy, which adapt to semi-solid process to form the high quality complex component one time.

New Recrystallisation Behaviour Seen in Magnesium Alloy Elektron 675

2012 ◽  
Vol 715-716 ◽  
pp. 171-172
Author(s):  
D. Randman ◽  
J. Corteen ◽  
W.M. Rainforth ◽  
B.P. Wynne ◽  
B. Davis
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Ternary System ◽  
Magnesium Alloys ◽  
Low Density ◽  
Fuel Savings ◽  
Specific Strength ◽  
High Specific Strength ◽  
Superior Mechanical Properties

There has recently been renewed interest in magnesium alloys from both the automotive and aerospace industries. Due to the low density (approximately 35% lower than aluminium) and high specific strength, these alloys can introduce significant weight savings, and consequently fuel savings, to both vehicles and aircraft. Elektron™ 675 is a new alloy based on the magnesium-yttrium-gadolinium ternary system, developed by Magnesium Elektron Ltd. for wrought applications. Elektron™ 675 has superior mechanical properties relative to the current commercially available wrought alloys AZ31B, WE43, and ZK60.

The influence of gadolinium on Al–Ti–C master alloy and its refining effect on AZ31 magnesium alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxue Fan ◽  
Hai Hao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Master Alloy ◽  
Cast Alloy ◽  
Az31 Magnesium Alloy ◽  
Synthesis Mechanism ◽  
Refining Effect ◽  
Master Alloys

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.

scholarly journals Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication

2021 ◽  
Author(s):  
Abdallah Elsayed
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Hot Tearing ◽  
Grain Refining ◽  
Grain Refiner ◽  
Structural Applications ◽  
Hot Tearing Susceptibility

For the A1-5Ti-1B grain refiner, the addition of 0.1 wt.% provided a 68 % reduction in grain size as compared to the unrefined AZ91E alloy at a holding time of five minutes. Grain growth restriction by TiB₂ particles was the source of grain refinement. With the addition of A1-5Ti-1B, only a small reduction in hot tearing susceptibility ws observed because large TiA1₃ particles bonded poorly with the eutectic and blocked feeding channels.The addition of 1.0 wt.% A1-1Ti-3B provided a grain size reduction of 63% as compared to the unrefined AZ91E alloy at a holding time of five minutes. The grain refinement with A1-1Ti-3B addition was attributed to a combination of TiB₂ grain growth restriction and A1B₂ nucleating sites. A significant reduction in hot tearing susceptibility was observed with A1-1Ti-3B addition as a result of a higher cooling rate and shorter local soldification time as compared to the AZ91E alloy. The reduction in hot tearing susceptibility was attributed to the good interface between eutectic and TiB₂ particles. Both grain refiners demonstrated a good resistance to fading during the holding times investigated. In addition, the AZ91E + A1-5Ti-1B and AZ91E + A1-1Ti-3B castings showed much fewer dislocation networks as compared to the untreated AZ91E casting.The development of efficient A1-Ti-B refiners can also improve castability of magnesium alloys. In addition, the fade resistant A1-Ti-B grain refiners can reduce operating costs and maintain productivity on the foundry floor. Thus, magnesium alloy with A1-Ti-B treatment have the potential for more demanding structural applications in the automobile and aerospace industries. Vehicle weight in the aerospace and automotive industries directly impacts carbon emissions and fuel efficiency. An increase in the use of lightweight materials for structural applications will result in lighter vehicles. Low density materials, such as magnesium (1.74 g/cm³) are a potential alternative to aluminium (2.70 g/cm³), to reduce component weight in structural applications.However, current magnesium alloys still do not have adequate mechanical properties and castability to meet the performance specifications of the automotive and aerospace industries. Grain refinement can significantly improve mechanical properties and reduce hot tearing during permanent mould casting. Recently, Al-Ti-B based grain refiners have shown potential in grain refining magnesium-aluminum alloys such as AZ91E. This study investigates the grain refining efficiency and fading of A1-5Ti-1B and A1-1Ti-3B in AZ91E magnesium alloy and their subsequent effect on hot tearing.The grain refiners were added at 0.1, 0.2, 0.5 and 1.0 wt.% levels. For the grain refinement and fading experiments, the castings were prepared using graphite moulds with holding times of 5, 10 and 20 minutes. For the hot tearing experiments, castings were produced representing the optimal addition level of each grain refiner. The castings were prepared using a permanent mould with pouring and mould temperatures of 720 and 180 ºC, respectively. The castings were characterized using SEM, TEM, optical microscopy and thermal analysis.

Microstructural and Mechanical Properties of a Solid-State Additive Manufactured Magnesium Alloy

2021 ◽  
pp. 1-21
Author(s):  
Thomas Robinson ◽  
Malcolm Williams ◽  
Harish Rao ◽  
Ryan P. Kinser ◽  
Paul Allison ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Process Parameters ◽  
Weight Ratio ◽  
Structural Components ◽  
Friction Stir ◽  
Magnesium Alloy Az31b

Abstract In recent years, additive manufacturing (AM) has gained prominence in rapid prototyping and production of structural components with complex geometries. Magnesium alloys, whose strength-to-weight ratio is superior compared to steel and aluminum alloys, have shown potential in lightweighting applications. However, commercial beam-based AM technologies have limited success with magnesium alloys due to vaporization and hot cracking. Therefore, as an alternative approach, we propose the use of a near net-shape solid-state additive manufacturing process, Additive Friction Stir Deposition (AFSD), to fabricate magnesium alloys in bulk. In this study, a parametric investigation was performed to quantify the effect of process parameters on AFSD build quality including volumetric defects and surface quality in magnesium alloy AZ31B. In order to understand the effect of the AFSD process on structural integrity in the magnesium alloy AZ31B, in-depth microstructure and mechanical property characterization was conducted on a bulk AFSD build fabricated with a set of acceptable process parameters. Results of the microstructure analysis of the as-deposited AFSD build revealed bulk microstructure similar to wrought magnesium alloy AZ31 plate. Additionally, similar hardness measurements were found in AFSD build compared to control wrought specimens. While tensile test results of the as-deposited AFSD build exhibited a 20 percent drop in yield strength, nearly identical ultimate strength was observed compared to the wrought control. The experimental results of this study illustrate the potential of using the AFSD process to additively manufacture Mg alloys for load bearing structural components with achieving wrought-like microstructure and mechanical properties.

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