scholarly journals Effect of Grain Refinement on the Dynamic, Mechanical Properties, and Corrosion Behaviour of Al-Mg Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1825
Author(s):  
Haitham M. Ahmed ◽  
Hussin A. M. Ahmed ◽  
Mohammed Hefni ◽  
Essam B. Moustafa
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Corrosion Behaviour ◽  
Cast Alloy ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Xrd Analysis ◽  
Optical Microscope ◽  
Mg Alloy ◽  
Resonance Frequencies

In this investigation, aluminium Al-2.5% Mg cast alloy was modified by adding 0.5 Ti and 0.1 B wt % modifiers to investigate their impact on the dynamic behaviour, as well as the mechanical and microstructure properties. The dynamic properties were analysed experimentally using a free vibration impact test and predicted using finite element methods. This study used a high-resolution polarised optical microscope to analyse the microstructure of the studied alloys and X-ray Powder Diffraction (XRD) analysis to determine the developed phases. Microstructure and mechanical properties were mostly enhanced as a result of grain refining during solidification and through the metal segregation process. The microstructure analysis of the modified alloy showed a significant improvement in the grain refinement; hence, the grains were 10 times finer than the cast alloy. The modified Al-2.5% Mg/Ti-B alloy demonstrated reduced inter-granular corrosion (IGC) than the Al-2.5% Mg standard cast alloy. By incorporating Ti-B modifiers into the composition of the cast Al-Mg alloy, the ultimate tensile strength (UTS), strain (ε), and hardness values (HV) were increased by 30.5%, 100%, and 18.18%, respectively. The dynamic properties of the modified alloy showed an enhancement in the resonant (fn) and damping ratio (ζ) by 7% and 68%, respectively. The predicted resonance frequencies of the investigated alloys showed results close to the experimental dynamic tests.

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 Strengthening of AA5754 Aluminum Alloy by DRECE Process Followed by Annealing Response Investigation

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 301 ◽  
Author(s):  
Przemysław Snopiński ◽  
Tomasz Tański ◽  
Klaudiusz Gołombek ◽  
Stanislav Rusz ◽  
Ondřej Hilser ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Dislocation Density ◽  
Grain Refinement ◽  
Grain Growth ◽  
Xrd Analysis ◽  
Strength Reduction ◽  
Electron Backscattered Diffraction

In this study, a dual rolls equal channel extrusion (DRECE) process has been applied for improving the mechanical properties of the 5754 alloy. Supplementary experiments involving metallography, electron backscattered diffraction (EBSD), and XRD tests were carried out to evaluate the effect of the DRECE process. XRD analysis showed that the maximum dislocation density was achieved after six DRECE passes, which were accompanied by the formation that is typical for low-strain structures. The increasing dislocation density, as well as grain refinement throughout DRECE deformation, resulted in an increase in the mechanical properties. Annealing of the as-deformed sample resulted in grain growth and strength reduction.

Mechanical Properties and Texture Evolution of AZ31 Mg Alloy during Equal Channel Angular Pressing

2005 ◽  
Vol 475-479 ◽  
pp. 545-548 ◽  
Author(s):  
Hyo Tae Jeong ◽  
Woo Jin Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Texture Evolution ◽  
Fiber Texture ◽  
Mg Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Az31 Mg Alloy ◽  
Similar Texture

Microstructure and texture evolution in the AZ31 Mg alloy subject to equal channel angular pressing (ECAP) have been investigated and correlated with the mechanical properties. When AZ31 Mg alloy was ECAPed up to 8 passes following the route Bc, grain refinement occurred effectively. Texture was also changed during ECAP. The original fiber texture of the extruded AZ31 Mg alloy changed to a new texture component of ] 1 3 2 5 )[ 1 1 01 ( , and the texture of ] 1 3 2 5 )[ 1 1 01 ( orientation was rotated to ] 0 2 5 7 )[ 6 4 13 ( orientation after 6-pass ECAP process. The variation of the strength with the pass number was explained by the texture and grain size. The strength data of AZ31 Mg alloys followed the standard Hall-Petch relationship when the similar texture was retained during the ECAP process. Otherwise the effect of texture on strength was dominant over the strengthening due to grain refinement.

Structure characteristics and mechanical properties of kaolinite soils. II. Effects of structure on mechanical properties

2006 ◽  
Vol 43 (6) ◽  
pp. 601-617 ◽  
Author(s):  
Y -H Wang ◽  
W -K Siu
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Shear Modulus ◽  
Critical State ◽  
Soil Structure ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Undrained Shear Strength ◽  
Interparticle Forces ◽  
Undrained Shear

This paper reports the effects of structure on the mechanical responses of kaolinite with known and controlled fabric associations. The dynamic properties and strength were assessed by resonant column tests and undrained triaxial compression tests, respectively. The experimental results demonstrate that interparticle forces and associated fabric arrangements influence the volumetric change under isotropic compression. Soils with different structures have individual consolidation lines, and the merging trend is not readily seen under an isotropic confinement up to 250 kPa. The dynamic properties of kaolinite were found to be intimately related to the soil structure. Stronger interparticle forces or higher degrees of flocculated structure lead to a greater small-strain shear modulus, Gmax, and a lower associated damping ratio, Dmin. The soil structure has no apparent influence on the critical-state friction angle (ϕ′c = 27.5°), which suggests that the critical stress ratio does not depend on interparticle forces. The undrained shear strength of kaolinite is controlled by its initial packing density rather than by any interparticle attractive forces, and yet the influence of the structure on the effective stress path is obvious.Key words: interparticle forces, shear modulus, damping ratio, stress–strain behavior, undrained shear strength, critical state.

Effect of Warm Deforming and Heat Treating on Microstructure and Mechanical Properties of Mg-Zn-Zr Magnesium Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 707-711
Author(s):  
Guan Lu ◽  
Ya Qin Yang ◽  
Bao Cheng Li ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Strengthening Effect ◽  
Zk60 Alloy ◽  
Cast Alloys

In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.

Effects of Hot Extrusion on Microstructure, Texture and Mechanical Properties of Mg-5Li-3Al-2Zn Alloy

2013 ◽  
Vol 773-774 ◽  
pp. 218-225
Author(s):  
Le Gan Hou ◽  
Rui Zhi Wu ◽  
Ji Qing Li ◽  
Jing Huai Zhang ◽  
Mi Lin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Grain Refinement ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Eutectic Structure ◽  
Basal Texture ◽  
Lamellar Eutectic ◽  
Lamellar Eutectic Structure

This work mainly studied the effects of hot extrusion on microstructure, texture and mechanical properties of Mg-5Li-3Al-2Zn alloy. The results show that the microstructures of as-cast and as-extruded alloys both consist of α-Mg matrix and lamellar eutectic structure (α-Mg and AlLi phases). During the hot extrusion, the large eutectic structure of as-cast alloy was crushed into small eutectic structure and the grains were effectively refined. A {0002} basal texture was formed after hot extrusion. The as-extruded alloy exhibits remarkably improved tensile properties, which is mainly attributed to the grain refinement and the formation of texture.

scholarly journals Enhancement of Fluidity and Mechanical Properties of Al – Si cast Alloy

2019 ◽  
Vol 9 (2) ◽  
pp. 246-251
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Copper Content ◽  
Cast Alloy ◽  
Base Material ◽  
Testing Conditions ◽  
Weight Percentage ◽  
Grain Sizes ◽  
Casting System ◽  
Different Temperatures

The aim of the study is to investigate the fluidity and mechanical properties of the Al-Si alloy by varying the copper content at three different temperatures with the effect of grain refinement. In this present examination a humble endeavour has been made to know the properties with an ease strategy for sand casting system. Al- Si aluminium alloy is chosen as the base material and copper powder; grain refinement and scrap were added as the compositions. The investigation has been furnished by variying the weight percentage of copper (0-4%), scrap (20-40%) and grain refinement (0-0.4%). Test examples were exposed to various testing conditions and properties have been upgraded. The tensile strength of the material increases with increase of percentage of copper content and the fluidity is balanced by addition of grain refinement. The comparison between microstructure images at 0% copper and 4% copper shows the variation of grain sizes.

scholarly journals Mg/ZrO2 Metal Matrix Nanocomposites Fabricated by Friction Stir Processing: Microstructure, Mechanical Properties, and Corrosion Behavior

2021 ◽  
Vol 9 ◽  
Author(s):  
Ke Qiao ◽  
Ting Zhang ◽  
Kuaishe Wang ◽  
Shengnan Yuan ◽  
Shengyi Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Grain Refinement ◽  
Friction Stir Processing ◽  
Biological Properties ◽  
Mg Alloy ◽  
Corrosion Properties ◽  
Metal Matrix Nanocomposites ◽  
Friction Stir ◽  
Average Grain Size

Magnesium (Mg) and its alloys have attached more and more attention because of their potential as a new type of biodegradable metal materials. In this work, AZ31/ZrO2 nanocomposites with good uniformity were prepared successfully by friction stir processing (FSP). The scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to characterize the microstructure of the composites. The mechanical properties, electrochemical corrosion properties and biological properties were evaluated. In addition, the effect of reinforced particles (ZrO2) on the microstructure and properties of the composite was studied comparing with FSP AZ31 Mg alloy. The results show that compared with the base metal (BM), the AZ31/ZrO2 composite material achieves homogenization, densification, and grain refinement after FSP. The combination of dynamic recrystallization and ZrO2 particles leads to grain refinement of Mg alloy, and the average grain size of AZ31/ZrO2 composites is 3.2 μm. After FSP, the c-axis of grain is deflected under the compression stress of shoulder and the shear stress of pin. The ultimate tensile strength (UTS) and yield strength (YS) of BM were 283 and 137 MPa, respectively, the UTS and YS of AZ31/ZrO2 composites were 427 and 217 MPa, respectively. The grain refinement and Orowan strengthening are the major strengthening mechanisms. Moreover, the corrosion resistance in simulated body fluid of Mg alloy is improved by grain refinement and the barrier effect of ZrO2.

scholarly journals Solidification, Microstructure and Mechanical Properties of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr Cast Alloy with Erbium Addition

2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Microstructure Analysis ◽  
Cooling Curve ◽  
Scanning Electron

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.

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