DSC and Microstructural Investigations of the Elektron 21 Magnesium Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1447-1452 ◽  
Author(s):  
Andrzej Kiełbus ◽  
Tomasz Rzychoń ◽  
Roman Przeliorz
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Magnesium Alloy ◽  
Solution Heat Treatment ◽  
Casting Alloy ◽  
Solution Hardening ◽  
Ageing Treatment ◽  
Aerospace Application ◽  
Different Temperatures ◽  
Cast Condition

The paper presents the results of DSC and microstructural investigations of Elektron 21 magnesium alloy in as cast condition and after solution hardening. Elektron 21 is a magnesium based casting alloy containing neodymium and gadolinium for used to at 200°C in aerospace application. The solution heat treatment was performed at 520°C/8h/water. Ageing treatment was performed at different temperatures 200, 250, 300 and 350°C, then quenched in air. The microstructure of Elektron 21 in as cast condition consists of primary solid solution α -Mg grains with eutectic α-Mg + Mg3(Nd,Gd) phase and regular precipitates of MgGd3 phase. After DSC investigations three exothermal signals has been observed. First exothermal signal at ~170÷245°C assigned to an undifferentiated formation of the metastable phases β” and β’ and the second one at ~280°C corresponded to the formation of a stable β (Mg3Nd) phase. The last signal at ~300°C was connected to the formation of Mg41Nd5 phase. Regular precipitates of MgGd3 phase have been also observed. TEM investigation confirmed that the Elektron 21 alloy precipitate from the solid solution according to the sequence of the following phases: α–Mgβ”β’β(Mg3Nd)Mg41Nd5

The Influence of High-Temperature Heat Treatment on the Microstructure of Mg-5Al-3Ca-0.7Sr-0.2Mn Magnesium Alloy

2013 ◽  
Vol 203-204 ◽  
pp. 246-249 ◽  
Author(s):  
Tomasz Rzychoń
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Precipitation Process ◽  
High Temperature Heat Treatment ◽  
Temperature Heat ◽  
Cast Condition ◽  
Temperature Heat Treatment

The paper presents results of microstructural investigations of Mg-5Al-3Ca-0.7Sr-0.2Mn (ACJM53) magnesium alloys in the as-cast condition and after heat treatment at 450°C for 4.5 hours. Two kinds of transformation were observed in ACJM53 alloy after heat treatment: (Mg,Al)2Ca (C36) → Al2Ca (C15) and Al3Mg13(Sr,Ca) → Mg17(Sr,Ca)2 transformations without the change in morphology of output compounds. Morphology of Mg2Ca (C14) have been changed from fine lamellar to globular and precipitation process of Al2Ca (C15) phase inside the grains of solid solution was found.

TEM Investigations of Electron 21 Magnesium Alloy

2007 ◽  
Vol 130 ◽  
pp. 175-180 ◽  
Author(s):  
Andrzej Kiełbus
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Solution Heat Treatment ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Air Cooling ◽  
Transmission Electron ◽  
The Matrix ◽  
Cast Condition ◽  
Cast Microstructure

The paper presents results of TEM investigations of Elektron 21 magnesium alloy in as cast condition and after heat treatment. The compositions of the Elektron 21 alloy used in the present study was Mg-2,7%wtNd-1,2%wtGd-0,47%wtZr. Solution heat treatment was performed at 520°C/8 h/water. Ageing treatments were performed at 200°C/4÷96h and 300°C/48h with cooling in air. The as-cast microstructure and microstructural evolution during heat treatment were examined by transmission electron microscopy. Samples were prepared using Gatan PIPS ion mill. Examinations were performed in a JEM 2010 ARP microscope. The microstructure of the cast alloy consists of a-Mg phase matrix with precipitates of Mg12(Ndx,Gd1-x) phase at grain boundaries. After solution treatment the Mg12(Ndx,Gd1-x) phase dissolved in the matrix. The ageing treatment applied after solution treatment with air-cooling caused precipitation of a β’ and β phases.

scholarly journals Studies of Post-Fabrication Heat Treatment of L-PBF-Inconel 718: Effects of Hold Time on Microstructure, Annealing Twins, and Hardness

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Wakshum M. Tucho ◽  
Vidar Hansen
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Additive Manufacturing ◽  
Inconel 718 ◽  
Solution Heat Treatment ◽  
Hold Time ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Annealing Twins ◽  
Complete Recrystallization

The widely adopted temperature for solid solution heat treatment (ST) for the conventionally fabricated Inconel 718 is 1100 °C for a hold time of 1 h or less. This ST scheme is, however, not enough to dissolve Laves and annihilate dislocations completely in samples fabricated with Laser metal powder bed fusion (L-PBF) additive manufacturing (AM)-Inconel 718. Despite this, the highest hardness obtained after aging for ST temperatures (970–1250 °C) is at 1100 °C/1 as we have ascertained in our previous studies. The unreleased residual stresses in the retained lattice defects potentially affect other properties of the material. Hence, this work aims to investigate if a longer hold time of ST at 1100 °C will lead to complete recrystallization while maintaining the hardness after aging or not. For this study, L-PBF-Inconel 718 samples were ST at 1100 °C at various hold times (1, 3, 6, 9, 16, or 24 h) and aged to study the effects on microstructure and hardness. In addition, a sample was directly aged to study the effects of bypassing ST. The samples (ST and aged) gain hardness by 43–49%. The high density of annealing twins evolved during 3 h of ST and only slightly varies for longer ST.

scholarly journals Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Solution Temperature ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Different Temperatures

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

Precipitate and Age Hardening Response of As-Cast Mg-8Yb-0.5Zr Magnesium Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 17-20
Author(s):  
Wen Bin Yu ◽  
Zhi Qian Chen ◽  
Mang Zhang ◽  
Zhou Yu
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Grain Boundaries ◽  
Microstructure Evolution ◽  
Solution Heat Treatment ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Intermetallic Phase ◽  
Age Hardening ◽  
Maximum Hardness

The precipitation hardening response of as-cast Mg-8Yb-0.5Zr magnesium alloy was investigated in the present work. The microstructure evolution of the alloy illustrated that Mg2Yb intermetallic phase was dissolved by solution heat treatment at 520°C for 12 hours. An apparent precipitation hardening response in Mg-8Yb-0.5Zr was discovered after artificial aging at 150°C, with maximum hardness increment of about 80 percent at the peak condition. It was found that the precipitates of the alloy were in the shape of two conjoined cosh and globe about 50 nm, and precipitated preferentially on grain boundaries and dislocations.

Formation of a Novel X Phase in Mg–Gd–Zn–Zr Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 623-626 ◽  
Author(s):  
Y.J. Wu ◽  
Li Ming Peng ◽  
X.Q. Zeng ◽  
D.L. Lin ◽  
W.J. Ding
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Phase Transformation ◽  
Grain Boundaries ◽  
Solution Heat Treatment ◽  
Long Period ◽  
Β Phase ◽  
Lpso Structure ◽  
Zr Alloy ◽  
Zr Alloys

The coherent fine-lamellae consisting of the 2H-Mg and the 14H-type long period stacking ordered (LPSO) structure within α'-Mg matrix have been observed in an as-cast Mg–Gd–Zn–Zr alloy. During subsequent solid solution heat treatment at 773 K, in addition to the lamellae within matrix, a novel lamellar X phase [Mg–(8.37±1.0)Zn–(11.32±1.0)Gd] with the 14H-type LPSO structure was transformed from the dendritical β phase. The 14H-type LPSO structure existing in Mg–Gd–Zn–Zr alloys derives from two variant ways: formation of the 14H-type LPSO structure comes from two variant means: i.e., the formation within matrix and the phase transformation from the β phase to the X phase in grain boundaries.

Strain Enhanced High Strength Cu–Ag–Zr Conductors

2009 ◽  
Vol 633-634 ◽  
pp. 707-715 ◽  
Author(s):  
Julia Lyubimova ◽  
Jens Freudenberger ◽  
Alexandere Gaganov ◽  
Hansjörg Klauss ◽  
Ludwig Schultz
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Phase Separation ◽  
Grain Growth ◽  
High Strength ◽  
Homogeneous Material ◽  
Growth Processes ◽  
Heat Treated ◽  
Different Temperatures ◽  
Zr Alloys

Recovery, recrystallisation and grain growth processes as well as the formation of a solid solution and the phase separation of a homogeneous material into a heterogeneous one are observed for Cu-Ag-Zr alloys heat-treated at different temperatures by means of mechanical, electrical and microstructural analyses. Heat treatments are shown to be an effective tool to enhance the strain to failure. If applied between several deformation steps the heat treatment causes an increase of both strain and strength limits.

Effect of Heat Treatments on the Bio-Corrosion Resistance of Magnesium Alloy Mg-8.0Al-1.0Zn-xGd

2011 ◽  
Vol 213 ◽  
pp. 497-501
Author(s):  
Lei Li ◽  
Rui He ◽  
Guo Jie Huang ◽  
Shui Sheng Xie
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Annealing Treatment ◽  
Microstructure Analysis ◽  
Β Phase ◽  
Α Phase ◽  
Treatment Procedures ◽  
Human Fluid

In order to improve the bio-corrosion resistance of magnesium alloy Mg-8.0Al-1.0Zn-xGd in the simulated human fluid, different heat treatment procedures were studied. Results showed that annealing treatment lowered the alloy’s corrosion resistance and hardness, while T6 treatment (solid solution+ aging) improved the alloy’s corrosion resistance and hardness. Microstructure analysis showed that the β phase dissolved into α phase after the annealing treatment. Hence, annealing treatment decreased the alloy’s corrosion resistance. However, lots of β-phases were precipitated in the T6 heat treatment, and they impeded the corrosion extending.

Effect of Heat Treatment on Phase Composition and Microstructure of Al-Cu-Fe Alloys with Quasicrystalline Phases

2014 ◽  
Vol 794-796 ◽  
pp. 833-838
Author(s):  
Marina Samoshina ◽  
Pavel Bryantsev
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Quasicrystalline Phase ◽  
Cast State ◽  
Equilibrium Conditions ◽  
Crystalline Phases ◽  
Different Temperatures ◽  
Fe Alloys ◽  
Cast Condition

The microstructure and phase composition of alloys Al-Cu-Fe in as-cast state and after heat treatment at different temperatures were investigated. The presence of a quasicrystalline phase Al65Cu20Fe15 which coexists with crystalline phases in as-cast condition is found. The formation of single quasicrystalline phase composition in Al - 40 wt.% Cu - 17 wt.% Fe alloy after annealing at 800 °C for 100 hours is established. After heat treatment, i.e. closer to equilibrium conditions, the quasicrystalline phase Al65Cu20Fe15 is transformed into quasicrystalline phase Al13Cu4Fe3 with more complicated lattice.

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