scholarly journals Effect of True Strains in Isothermal abc Pressing on Mechanical Properties of Ti49.8Ni50.2 Alloy

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1313
Author(s):  
Oleg Kashin ◽  
Konstantin Krukovskii ◽  
Aleksandr Lotkov ◽  
Victor Grishkov
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
True Strain ◽  
Main Idea ◽  
Strain Curve ◽  
Subgrain Structure ◽  
Average Grain Size ◽  
Abc Pressing

The paper analyzes the microstructure and mechanical properties of Ti49.8Ni50.2 alloy (at.%) under uniaxial tension at room temperature after isothermal abc pressing to true strains e = 0.29 − 8.44 at T = 723 K. The analysis shows that as the true strain e is increased, the grain–subgrain structure of the alloy is gradually refined. This leads to an increase in its yield stress σy and strain hardening coefficient θ = dσ/dε at linear stage III of its tensile stress–strain curve according to the Hall–Petch relation. However, the ultimate tensile strength remains invariant to such refinement. The possible mechanism is proposed to explain why the ultimate tensile strength can remain invariant to the average grains size (dav). It is assumed that the sharp increase of the ultimate tensile strength σUTS begins when (dav) is less than the critical average grain size (dav)cr. In our opinion, for the investigated alloy (dav)cr ≈ 0.5 µm. In our study, the attained average grain size is larger the critical one. The main idea of the mechanism is next. In alloys with an average grain size (dav) less than the critical one, a higher external stress is required for the nucleation and propagation of the main crack.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

scholarly journals Effect of Heat Treatment on Mechanical Properties and Microstructure Morphology of Low-Alloy High-Strength Steel

2016 ◽  
Vol 61 (2) ◽  
pp. 475-480
Author(s):  
K. Bolanowski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
High Strength Steel ◽  
High Strength ◽  
Strengthening Phase ◽  
Average Grain Size

Abstract The paper analyzes the influence of different heat treatment processes on the mechanical properties of low-alloy high-strength steel denoted by Polish Standard (PN) as 10MnVNb6. One of the findings is that, after aging, the mechanical properties of rolled steel are high: the yield strength may reach > 600 MPa, and the ultimate tensile strength is > 700 MPa. These properties are largely dependent on the grain size and dispersion of the strengthening phase in the ferrite matrix. Aging applied after hot rolling contributes to a considerable rise in the yield strength and ultimate tensile strength. The process of normalization causes a decrease in the average grain size and coalescence (reduction of dispersion) of the strengthening phase. When 10MnVNb6 steel was aged after normalization, there was not a complete recovery in its strength properties.

Effect of Bi on Microstructure and Mechanical Properties of Extruded AZ80-2Sn Magnesium Alloy

2018 ◽  
Vol 37 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Hansong Xue ◽  
Xinyu Li ◽  
Weina Zhang ◽  
Zhihui Xing ◽  
Jinsong Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

AbstractThe effects of Bi on the microstructure and mechanical properties of AZ80-2Sn alloy were investigated. The results show that the addition of Bi within the as-cast AZ80-2Sn alloy promotes the formation of Mg3Bi2 phase, which can refine the grains and make the eutectic phases discontinuous. The addition of 0.5 % Bi within the as-extruded AZ80-2Sn alloy, the average grain size decreases to 12 μm and the fine granular Mg17Al12 and Mg3Bi2 phases are dispersed in the α-Mg matrix. With an increase in Bi content, the Mg17Al12 and Mg3Bi2 phases become coarsened and the grain size increases. The as-extruded AZ80-2Sn-0.5 %Bi alloy has the optimal properties, and the ultimate tensile strength, yield strength and elongation are 379.6 MPa, 247.1 MPa and 14.8 %, respectively.

Microstructure and Mechanical Properties of Mg96Y3Zn1 Alloy Processed by Equal Channel Angular Pressing

2011 ◽  
Vol 682 ◽  
pp. 49-54
Author(s):  
Bin Chen ◽  
Chen Lu ◽  
Dong Liang Lin ◽  
Xiao Qin Zeng
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Equal Channel Angular Pressing ◽  
Ultrafine Grains ◽  
Angular Pressing ◽  
Average Grain Size

The Mg96Y3Zn1 alloy processed by equal channel angular pressing has been investigated. It was found that the Mg96Y3Zn1 alloy processed by ECAP obtained ultrafine grains and exhibits excellent mechanical properties. After ECAP, the average grain size of Mg96Y3Zn1 alloy refined to about 400 nm. The highest strengths with yield strength of 381.45MPa and ultimate tensile strength of 438.33MPa were obtained after 2 passes at 623K. It was found that cracks were preferentially initiated and propagated in the interior of X-phase during the tensile test. As a result, the elongation of alloy is decreased with pass number increasing.

Ultrafine-Grained Structure and Mechanical Properties of a High-Mn Twinning Induced Plasticity Steel

2016 ◽  
Vol 838-839 ◽  
pp. 392-397 ◽  
Author(s):  
Pavel Kusakin ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev ◽  
Dmitri Molodov
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Cold Rolling ◽  
Twip Steel ◽  
True Strain ◽  
Total Elongation ◽  
Recrystallization Annealing

The influence of thermo-mechanical treatment consisting of cold rolling followed by recrystallization annealing on the grain size and mechanical properties of a high-Mn TWIP steel was studied. An Fe-23Mn-0.3C-1.5Al TWIP steel (wt. %) was subjected to extensive cold rolling with a reduction of 80% (true strain of ∼1.6) and then annealed in the temperature interval ranging from 400 to 900 °C during 20 minutes. Recovery processes took place below 500 °C, partial recrystallization was evident at ~550°C and fully recrystallized structure evolved after annealing at 600 °C and higher. The static recovery resulted in a slight decrease in the yield strength from 1400 MPa to 1250 MPa and the ultimate tensile strength from 1540 MPa to 1400 MPa whereas the total elongation of 4% did not changed. The recrystallization development led to a drastic drop of strength and an increase in ductility. The yield strength of 225 MPa, the ultimate tensile strength of 700 MPa and the total elongation of 79% was obtained after annealing at 900 °C. Correspondingly, the grain size increased from 0.2 μm to 6.2 μm with increase in anneal temperature from 550 to 900°C.

Effects of Mg Content on Electric and Mechanical Properties of Al–Zn–Cu Based Alloys

2021 ◽  
Vol 21 (3) ◽  
pp. 2015-2018
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Kyu-Seok Lee ◽  
Sung-Ho Lee ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Al Alloys ◽  
Lattice Constants ◽  
Cu Alloy ◽  
Average Grain Size ◽  
Mg Content

Microstructure and properties of Al–2 wt.%Zn–1 wt.%Cu–xMg (x = 0.1, 0.3, 0.5, 0.7 wt.%) alloy extrusion materials were investigated. The lattice constants for the (311) plane increased to 4.046858, 4.048483, 4.050114 and 4.051149 Å with the addition of 0.1, 0.3, 0.5, and 0.7 wt.% of elemental Mg. The average grain size of the as-extruded Al alloys was found to be 328.7, 297.7, 187.0 and 159.3 μm for the alloys with 0.1, 0.3, 0.5, and 0.7 wt.% Mg content, respectively. The changes in the electrical conductivity by the addition of elemental Mg in Al–2 wt.%Zn–1 wt.%Cu alloy was determined, and it was found that for the addition of 0.1, 0.3, 0.5, and 0.7 wt.% Mg, the conductivity decreased to 51.62, 49.74, 48.26 and 46.80 %IACS. The ultimate tensile strength of Al–2 wt.%Zn–1 wt.%Cu–0.7 wt.%Mg alloy extrusion was increased to 203.55 MPa. Thus, this study demonstrated the correlation between the electrical conductivity and strength for the Al–2 wt.%Zn–1 wt.%Cu–xMg alloys.

Microstructure Evolution of AZ91D Magnesium Alloy Semi-solid Billets Prepared by a New SIMA Method

2006 ◽  
Vol 116-117 ◽  
pp. 132-135 ◽  
Author(s):  
Ju Fu Jiang ◽  
Shou Jing Luo
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Extrusion ◽  
Isothermal Treatment ◽  
Az91d Magnesium Alloy ◽  
Average Grain Size ◽  
Semi Solid

By using equal channel angular extrusion (ECAE) as strain induced step in strain induced melt activated (SIMA) and completing melt activated step by using semi-solid isothermal treatment, a new SIMA method is introduced firstly. The results show that semi-solid billet with highly spheroidal and homogeneous grains with the average grain size of 20μm can be prepared by new SIMA method. High mechanical properties, such as ultimate tensile strength of 321.8MPa and elongation of 15.2% are obtained in magazine plate components thixoforged using semi-solid billet prepared by new SIMA.

Investigation on the anisotropy behavior of copper strips processed by a combination of FSP and ECAP

2021 ◽  
pp. 146442072110095
Author(s):  
PM Keshtiban ◽  
R Abdi Behnagh ◽  
F Bashirzadeh ◽  
Rasol Javadzadeh ◽  
Abolfazl Mohsenzadeh
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Base Metal ◽  
Pure Copper ◽  
Copper Sheet ◽  
Friction Stir ◽  
Refined Microstructure ◽  
Average Grain Size

In this study, friction stir processed (FSP) pure copper sheet was equal channel angular pressed (ECAP). The purpose was to investigate the influence of ECAP on the microstructure and mechanical properties of the FSP-treated copper sheet. The dynamically recrystallized grained structure with the average grain size of ∼13 µm was found in the stir zone of the FSP. It was also revealed that FSP caused the enhancement of ultimate tensile strength compared to that of the base metal. Also, it was observed that ECAP led to further grain refinement and a tighter distribution of grains. A refined microstructure with an average grain size of ∼ 2 µm was achieved in copper sheets through FSP, followed by ECAP. The tensile strengths of the ECAP specimens were significantly increased to about 61 and 50% compared to the strengths of base metal and FSP, respectively. An overview of the results of this study showed that combined FSP/ECAP is an effective method for the mechanical improvement of the pure copper sheets.

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.

Effect of Nd Content and Heat Treatment on Microstructure and Mechanical Properties of Mg-Zn-Nd Alloy

2017 ◽  
Vol 898 ◽  
pp. 124-130 ◽  
Author(s):  
Shu Min Xu ◽  
Xin Ying Teng ◽  
Xing Jing Ge ◽  
Jin Yang Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Cast Alloy ◽  
Second Phase ◽  
Casting Method ◽  
Magnesium Matrix ◽  
Microstructure And Mechanical Properties

In this paper, the microstructure and mechanical properties of the as-cast and heat treatment of Mg-Zn-Nd alloy was investigated. The alloy was manufactured by a conventional casting method, and then subjected to a heat treatment. The results showed that the microstructure of as-cast alloy was comprised of α-Mg matrix and Mg12Nd phase. With increase of Nd content, the grain size gradually decreased from 25.38 μm to 9.82 μm. The ultimate tensile strength and elongation at room temperature of the Mg94Zn2Nd4 alloy can be reached to 219.63 MPa and 5.31%. After heat treatment, part of the second phase dissolved into the magnesium matrix and the grain size became a little larger than that of the as-cast. The ultimate tensile strength was declined by about 2.5%, and the elongation was increased to 5.47%.

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