Microstructure, Mechanical Properties, Electric and Thermal Conductivity of the As-Extruded Al-x(1.0 wt.% Zn + 0.5 wt.% Cu) Alloys (x = 1, 2 and 4)

2020 ◽  
Vol 20 (7) ◽  
pp. 4248-4252
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Intermetallic Compounds ◽  
Extrusion Process ◽  
Al Alloy ◽  
Homogenization Treatment ◽  
Solid Solution Strengthening ◽  
Cu Content ◽  
Average Grain Size ◽  
Solution Strengthening

In this research, effects of Zn and Cu content on microstructure, mechanical properties, electric and thermal conductivity of the as-extruded Al-x(Zn+0.5Cu) alloys were investigated. As the content of Zn and Cu increased, the area ratio of Al2Cu intermetallic compounds increased. After homogenization treatment and extrusion process, most of Al2Cu intermetallic compounds was disappeared due to solution in Al matrix of Cu atoms. As the (Zn+0.5Cu) content increased from 1 to 2 wt.%, the average grain size decreased remarkably from 645 to 227 μm due to the dynamic recrystallization caused by the solute Zn and Cu atoms during the extrusion. With increasing Zn and Cu additions, the thermal conductivity was decreased from 225 (x = 1) to 208 (x = 2) and 183 W/mK (x = 4) due to electric scattering by solute Zn and Cu atoms. The ultimate tensile strength (UTS) of the as-extruded Al-x(1Zn+0.5Cu) alloys improved remarkably from 77 (x = 1) to 142 MPa (x = 4) as Zn and Cu content increased, and the elongation increased from 30 to 33%. This improvement in the strength resulted from the grain refinement and solid solution strengthening due to the solute Zn and Cu atoms. The Zn and Cu addition in Al alloy played an important role in thermal conductivity and mechanical properties.

Microstructure, Electrical and Thermal Conductivity of the As-Extruded Al-xMM (Mischmetal) Based Alloys

2021 ◽  
Vol 21 (3) ◽  
pp. 1984-1989
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Seong-Ho Lee ◽  
Gyu-Seok Lee ◽  
Hyeon-Taek Son
Keyword(s):  
Thermal Conductivity ◽  
Intermetallic Compounds ◽  
Fine Particles ◽  
Hot Extrusion ◽  
Wide Band ◽  
Extrusion Process ◽  
Eutectic Phase ◽  
Extrusion Ratio ◽  
Average Grain Size ◽  
Cast Alloys

The effect of addition of Mischmetal (MM) on the microstructure, electrical and thermal conductivity, and mechanical properties of the as-extruded Al-MM based alloys were investigated. The studied AlxMM alloys (where x = 0.2, 0.5, 1.0, 1.5, 2.0 and 5.0 wt.%) were cast and homogenized at 550 °C for 4 h. The cast billets were extruded into 12 mm bars with an extrusion ratio of 39 at 550 °C. The addition of MM resulted in the formation of Al11(Ce, La)3 intermetallic compounds and the area fraction of these intermetallic compounds increased with an increase in the MM content. The Al11(Ce, La)3 phase, which was distributed in the as-cast alloys, was crushed into fine particles and arrayed along the extruded direction during the extrusion process. In particular, these intermetallic compounds in the extruded Al-5.0MM alloy were distributed with a wide-band structure due to the fragmentation of the eutectic phase with a lamellar structure. As the MM content increased from 1.0 wt.% to 5.0 wt.%, the average grain size decreased remarkably from 740 to 73 μm. This was due to formation of Al11(Ce, La)3 particles during the hot extrusion process, which promoted dynamic recrystallization and suppression of grain growth. The electrical and thermal conductivity of the extruded alloys containing up to 2.0 wt.% MM were around 60.5% IACS and 230 W/m · K, respectively. However, the electrical and thermal conductivity of the extruded alloy with 5.0 wt.% MM decreased to 55.4% IACS and 206 W/m · K, respectively. As the MM content increased from 1.0 wt.% to 5.0 wt.%, the ultimate tensile strength (UTS) was improved remarkably from 74 to 119 MPa which was attributed to the grain refinement and formation of Al11(Ce, La)3 intermetallic compounds by the addition of MM.

Solid-Solution Strengthening Effect of Vanadium Addition to Iron-Modified L12 Titanium Trialuminides

1994 ◽  
Vol 364 ◽  
Author(s):  
Tohru Takahashi ◽  
Tadashi Hasegawa
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Intermetallic Compounds ◽  
Argon Atmosphere ◽  
Strengthening Effect ◽  
Cubic Symmetry ◽  
Solid Solution Strengthening ◽  
Arc Melting ◽  
Solution Strengthening ◽  
Cubic Structure

AbstractTwo types of aluminum–titanium–iron–vanadium ( Al–Ti–Fe–V ) quarternary intermetallic compounds have been prepared by arc melting under argon atmosphere. Their compositions were nominally Al66Ti25Fe6V3 and Al66Ti25Fe3V6. These alloys are based on the iron–modified titanium trialuminide with L12 cubic structure. Vanadium addition up to about 6 mol% did not destroy the cubic symmetry, and L12 solid solution compounds were produced in these two Al–Ti–Fe–V quarternary alloys. Microstructure and mechanical properties have been investigated. It has been demonstrated that vanadium addition to iron–modified L12 titanium trialuminides can enhance their strength.

Influence of Rare Earth and Fe Addition on the Microstructure and Mechanical Properties of Al-B Alloy

2021 ◽  
Vol 16 (5) ◽  
pp. 806-811
Author(s):  
Hyo-Sang Yoo ◽  
Yong-Ho Kim ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Rare Earth ◽  
Intermetallic Compounds ◽  
Al Alloy ◽  
High Angle ◽  
Average Grain Size ◽  
Metallic Compounds ◽  
Annealed Copper ◽  
Fe Addition

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of as-cast and as-extruded Al–B based alloys with the addition of Fe and rare earth (RE) were investigated. The melted aluminum alloy was maintained at 750 °C and then poured into a mould at 200 °C. Aluminum alloys were hot-extruded into a rod that was 12 mm in thickness with a reduction ratio of 39:1. The addition of Fe and RE resulted in the formation of Al11RE3 and Al3Fe intermetallic compounds and the area fraction of these inter-metallic compounds increased with increasing Fe and RE contents. As the amount of Fe and RE increased, the average grain size of the extruded Al alloy decreased to 798.6, 196.1, and 21.9 µm, and the high-angle grain boundaries fraction increased to 24.8, 27.9, and 60.7%. In the case of cast materials, low electrical conductivity was shown by porosity and fine casting defects. As the Fe and RE contents increased, the electrical conductivity of the extruded Al–B alloy decreased to 62.3, 59.6 and 55.0% International Annealed Copper Standard. As the Fe and RE content increased the ultimate tensile strength improved from 90.8 to 112.9 MPa which was attributed to the grain refinement and formation of Al11RE3 and Al3Fe intermetallic compounds by the addition of Fe and RE.

scholarly journals Novel Co-Cu-Based Immiscible Medium-Entropy Alloys with Promising Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 238
Author(s):  
Sujung Son ◽  
Jongun Moon ◽  
Hyeonseok Kwon ◽  
Peyman Asghari Rad ◽  
Hidemi Kato ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Binary System ◽  
Design Methodology ◽  
Miscibility Gap ◽  
Face Centered Cubic ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Face Centered ◽  
Strength And Ductility ◽  
Cobalt Copper

New AlxCo50−xCu50−xMnx (x = 2.5, 10, and 15 atomic %, at%) immiscible medium-entropy alloys (IMMEAs) were designed based on the cobalt-copper binary system. Aluminum, a strong B2 phase former, was added to enhance yield strength and ultimate tensile strength, while manganese was added for additional solid solution strengthening. In this work, the microstructural evolution and mechanical properties of the designed Al-Co-Cu-Mn system are examined. The alloys exhibit phase separation into dual face-centered cubic (FCC) phases due to the miscibility gap of the cobalt-copper binary system with the formation of CoAl-rich B2 phases. The hard B2 phases significantly contribute to the strength of the alloys, whereas the dual FCC phases contribute to elongation mitigating brittle fracture. Consequently, analysis of the Al-Co-Cu-Mn B2-strengthened IMMEAs suggest that the new alloy design methodology results in a good combination of strength and ductility.

scholarly journals The Extrusion and SPS of Zirconium–Copper Powders and Studies of Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3560
Author(s):  
Tomasz Skrzekut ◽  
Grzegorz Boczkal ◽  
Adam Zwoliński ◽  
Piotr Noga ◽  
Lucyna Jaworska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Room Temperature ◽  
Intermetallic Phase ◽  
Extrusion Process ◽  
Strength Properties ◽  
Plasma Sintering ◽  
Copper Powders ◽  
Spark Plasma ◽  
Zirconium Copper

Zr-2.5Cu and Zr-10Cu powder mixtures were consolidated in the extrusion process and using the spark plasma sintering technique. In these studies, material tests were carried out in the fields of phase composition, microstructure, hardness and tensile strength for Zr-Cu materials at room temperature (RT) and 400 °C. Fractography analysis of materials at room temperature and 400 °C was carried out. The research took into account the anisotropy of the materials obtained in the extrusion process. For the nonequilibrium SPS process, ZrCu2 and Cu10Zr7 intermetallic compounds formed in the material at sintering temperature. Extruded materials were composed mainly of α-Zr and ZrCu2. The presence of intermetallic compounds affected the reduction in the strength properties of the tested materials. The highest strength value of 205 MPa was obtained for the extruded Zr-2.5Cu, for which the samples were cut in the direction of extrusion. For materials with 10 wt.% copper, more participation of the intermetallic phase was formed, which lowered the mechanical properties of the obtained materials. In addition to brittle intermetallic phases, the materials were characterized by residual porosity, which also reduced the strength properties.

scholarly journals A Short Review on the Phase Structures, Oxidation Kinetics, and Mechanical Properties of Complex Ti-Al Alloys

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1677
Author(s):  
Hooi Peng Lim ◽  
Willey Yun Hsien Liew ◽  
Gan Jet Hong Melvin ◽  
Zhong-Tao Jiang
Keyword(s):  
Mechanical Properties ◽  
Oxidation Kinetics ◽  
Mass Gain ◽  
Short Review ◽  
Al Alloys ◽  
Alloying Elements ◽  
Isothermal Exposure ◽  
Solid Solution Strengthening ◽  
Phase Structures ◽  
Solution Strengthening

This paper reviews the phase structures and oxidation kinetics of complex Ti-Al alloys at oxidation temperatures in the range of 600–1000 °C. The mass gain and parabolic rate constants of the alloys under isothermal exposure at 100 h (or equivalent to cyclic exposure for 300 cycles) is compared. Of the alloying elements investigated, Si appeared to be the most effective in improving the oxidation resistance of Ti-Al alloys at high temperatures. The effect of alloying elements on the mechanical properties of Ti-Al alloys is also discussed. Significant improvement of the mechanical properties of Ti-Al alloys by element additions has been observed through the formation of new phases, grain refinement, and solid solution strengthening.

Effect of Ti Element on Microstructure and Properties of Cu-Cr Alloy

2015 ◽  
Vol 817 ◽  
pp. 307-311 ◽  
Author(s):  
Peng Chao Zhang ◽  
Jin Chuan Jie ◽  
Yuan Gao ◽  
Tong Min Wang ◽  
Ting Ju Li
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Spherical Shape ◽  
Precipitation Strengthening ◽  
Peak Hardness ◽  
Ti Alloy ◽  
Strengthening Mechanisms ◽  
Vacuum Melting ◽  
Solid Solution Strengthening ◽  
Solution Strengthening

The Cu-Cr and Cu-Cr-Ti alloy plates were prepared by vacuum melting and plastic deformation. The effect of slight Ti element on microstructure and mechanical properties of Cu-Cr alloy was discussed. The result shows that Cr particles with spherical shape precipitated from Cu matrix after aging. Plenty Ti atoms dissolved in the vicinity of Cr particles and there were still parts of solid solution Ti atoms in other regions. Improvements in peak hardness and softening resistance were achieved with the addition of Ti element in Cu-Cr alloy. The addition of 0.1 wt.% Ti element makes Cu-Cr alloy possess tensile strength of 565 MPa and hardness of 185.9 HV after aging at 450 °C for 120 min, which can be attributed to multiple strengthening mechanisms, i.e. work hardening, solid solution strengthening and precipitation strengthening.

Effect of Li on Mechanical Properties and Electrical Conductivity of the Al–Zn–Cu–Mg Based Alloys

2021 ◽  
Vol 21 (9) ◽  
pp. 4897-4901
Author(s):  
Hyo-Sang Yoo ◽  
Yong-Ho Kim ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Tensile Strength ◽  
Spherical Particles ◽  
Al Alloy ◽  
High Angle ◽  
Average Grain Size ◽  
Strength Improvement ◽  
Li Content

In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al–Zn–Cu–Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al–Zn–Cu–Mg–xLi alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 µm, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.

scholarly journals Mechanical and Thermal Conductivity Properties of Enhanced Phases in Mg-Zn-Zr System from First Principles

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2010
Author(s):  
Shuo Wang ◽  
Yuhong Zhao ◽  
Huijun Guo ◽  
Feifei Lan ◽  
Hua Hou
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Intermetallic Compounds ◽  
Elastic Constants ◽  
First Principles ◽  
Strengthening Phases ◽  
Zr Alloy ◽  
Zr Alloys

In this paper, the mechanical properties and minimum thermal conductivity of ZnZr, Zn2Zr, Zn2Zr3, and MgZn2 are calculated from first principles. The results show that the considered Zn-Zr intermetallic compounds are effective strengthening phases compared to MgZn2 based on the calculated elastic constants and polycrystalline bulk modulus B, shear modulus G, and Young’s modulus E. Meanwhile, the strong Zn-Zr ionic bondings in ZnZr, Zn2Zr, and Zn2Zr3 alloys lead to the characteristics of a higher modulus but lower ductility than the MgZn2 alloy. The minimum thermal conductivity of ZnZr, Zn2Zr, Zn2Zr3, and MgZn2 is 0.48, 0.67, 0.68, and 0.49 W m−1 K−1, respectively, indicating that the thermal conductivity of the Mg-Zn-Zr alloy could be improved as the precipitation of Zn atoms from the α-Mg matrix to form the considered Zn-Zr binary alloys. Based on the analysis of the directional dependence of the minimum thermal conductivity, the minimum thermal conductivity in the direction of [110] can be identified as a crucial short limit for the considered Zn-Zr intermetallic compounds in Mg-Zn-Zr alloys.

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