scholarly journals The microstructure evolution and mechanical properties improvement of the AZ61 alloy by adding Sc

2021 ◽  
Author(s):  
Honggang Zhang ◽  
Jinhui Wang ◽  
Hongbin Ma ◽  
Yuan Yuan ◽  
Yongfeng Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Secondary Phase ◽  
Grain Sizes ◽  
Az61 Alloy ◽  
Mg17al12 Phase

Abstract The improvement of mechanical properties and the microstructure evolution through adding Sc to AZ61magnesium alloy were studied. The results indicated that the Mg17Al12 phase in the extruded AZ61 alloy was mainly distributed around the sub-structured and fine deformed grains, resulting in the nonuniform microstructure. The addition of Sc could effectively suppress the band-like precipitation of Mg17Al12 phase and improve the uniformity of microstructure. The grain sizes of the extruded alloys showed a trend of first decreasing and then increasing with the increase of Sc, which was mainly attributed to the secondary phase. The AZ61-0.5Sc alloy exhibited the best mechanical properties, its ultimate tensile strength and yield strength were 14.8MPa and 40.8MPa higher than those of the extruded AZ61 alloy, respectively, which was ascribed to the fine grains and abundant secondary phase in the alloy.

Evolution of phases during tempering of P91 steel at 760℃ for varying tempering time and their effect on microstructure and mechanical properties

2016 ◽  
Vol 231 (6) ◽  
pp. 1141-1161 ◽  
Author(s):  
C Pandey ◽  
MM Mahapatra
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Secondary Phase ◽  
Particle Spacing ◽  
Carbide Particles ◽  
Tempering Time

In the present investigation, a systematic study has been undertaken with regard to the effects of tempering time on room temperature mechanical properties of P91 (X10CrMoVNNB9-1) steel. Samples cut from P91 (X10CrMoVNNB9-1) industrial pipe were normalized at 1040 ℃ for 40 min and then tempered at 760 ℃ for different tempering times starting from 2 h to 8 h. Detailed analysis of microstructure, particle size, inter-particle spacing, and secondary phase carbide particles of the tempered samples was conducted by secondary electron microscopy technique. Optical microscopy was also utilized to characterize the tempered samples and for the measurement of grain size. In order to reveal the various phases formed during tempering of P91 (X10CrMoVNNB9-1) steel, X-ray diffraction was carried out . To study the fracture surface morphology of tensile tested and impact tested specimen field-emission scanning electron microscopy was carried out. The effect of tempering time on the microstructural parameters revealed an increase in grain size up to 4 h of tempering and then decreased because of recrystallization. The coarsening of secondary phase carbide particles M23C6 was revealed with an increase in tempering time. As a consequence, yield strength, hardness, and ultimate tensile strength were observed to decrease with increase in the tempering time. However, a drastic change was observed in the yield strength, ultimate tensile strength, and toughness after tempering for 6 h. From the present study, it was concluded that optimum combination of yield stress, ultimate tensile strength, hardness, and toughness obtained after tempering at 760 ℃ for 6 h.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

scholarly journals PENGARUH PERSENTASE REDUKSI WARM ROLLING TERHADAP SIFAT MEKANIK PADUAN Cu-Zn 70/30

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Ayu Rizeki Ridhowati ◽  
Eka Febriyanti ◽  
Rini Riastuti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Warm Rolling ◽  
Holding Time ◽  
Partial Recrystallization ◽  
Homogenization Process ◽  
Thermomechanical Method

Warm rolling is one of the thermomechanical method has several advantages such as produces high mechanical properties, but does not decrease % elongation and toughness value because partial recrystallization phenomenon that produces micron-sized new grain. This paper reports the results of an investigation carried out on the effects of holding time annealing to mechanical properties Cu-Zn 70/30 alloy. These alloy after homogenization process and quenched in the air then heated to temperature of 300°C, later the heated copper samples are warm rolled at 25%, 30%, and 35% reduction, after that heated at temperature 300°C and held during 120 minutes. Then sample is experienced rewarm rolling with reduction 25%, 30%, and 35%. The results obtained showed that the ultimate tensile strength and yield strength are higher proportional with the increasing of % reduction, their values are 501,1 MPa; 599,3 MPa; later decrease to 546, 5 MPa and to yield strength are 441,8 MPa; 466,1 MPa; then decrease to 458,6 MPa. Moreover hardness value increase proportional with % reduction such as 154 HV; 162 HV; after that decrease to 160 HV While, % elongation decreases inversely proportional with % reduction namely 12,4%; 8,2%; later increase to 11,2 %. It is caused of the partial recrystallization phenomenon as evidenced by the presence micron-sized.AbstrakWarm rolling merupakan salah satu metode termomekanik yang mempunyai beberapa keuntungan yaitu salah satunya menghasilkan sifat mekanik yang tinggi, namun tidak mengurunkan nilai keuletan karena adanya fenomena rekristalisasi parsial yang menghasilkan butiran baru berbentuk micron. Paper ini menjelaskan tentang hasil penelitian berupa pengaruh persentase reduksi terhadap sifat mekanis paduan Cu-Zn 70/30. Paduan Cu-Zn 70/30 setelah dilakukan proses homogenisasi dan didinginkan di udara lalu dipanaskan ke suhu 300°C, kemudian masing-masing dilakukan warm rolling dengan persentase reduksi sebesar 25%, 30%, dan 35% kemudian ditahan di suhu 300°C dalam waktu 120 menit. Selanjutnya sampel dilakukan rewarm rolling dengan persentase reduksi sebesar 25%, 30%, dan 35%. Hasil penelitian yang dilakukan antara lain nilai kekuatan tarik (UTS dan YS) yang semakin tinggi sebanding dengan peningkatan % reduksi warm rolling yaitu masing-masing untuk nilai UTS sebesar 501,1 MPa; 599,3 MPa; lalu menurun menjadi 546,5 MPa serta untuk nilai kekuatan luluh sebesar 441,8 MPa; 466,1 MPa; lalu menurun menjadi 458,6 MPa. Selain itu, nilai kekerasan meningkat sebanding dengan peningkatan % reduksi warm rolling masing-masing sebesar 154 HV; 162 HV; lalu menurun menjadi 160 HV. Sedangkan persentase elongasi semakin menurun berbanding terbalik dengan peningkatan % reduksi masing-masing sebesar 12,4%; 8,2%; lalu meningkat menjadi 11,2%. Hal tersebut disebabkan karena adanya fenomena rekristalisasi parsial yang dibuktikan dengan kehadiran butir kecil berukuran mikron.Keywords : Cu-Zn 70/30 alloy, warm rolling, anneal, % reduction, mechanical properties

MICROSTRUCTURAL INVESTIGATION AND MECHANICAL PROPERTIES OF THIXOFORMED AL-6SI-XCU-0.3MG ALLOYS

2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Mohd Shukor Salleh ◽  
Nurul Naili Mohamad Ishak ◽  
Saifudin Hafiz Yahaya
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Intermetallic Phase ◽  
Dendritic Microstructure ◽  
Microstructural Investigation ◽  
Cu Content ◽  
Cooling Slope ◽  
Cooling Slope Casting

In this study, the effect of different amounts of copper (CU) on the microstructure and mechanical properties of thixoformed Al-6Si-xCu-0.3Mg (x= 3, 4 and 5, mass fraction, %) were investigated. The alloys were prepared via cooling slope casting technique, before there were thixoformed using compression press. All of the alloys were then characterized using optical microscope (OM), scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results obtained revealed that cooling slope casting produced a non-dendritic microstructure and the intermetallic phase in the thixoformed samples was refined and evenly distributed. The results also revealed that as the Cu content in the alloy increases, the hardness and tensile strength of the thixoformed alloys also increase. The hardness of thixoformed Al-6Si-3Cu was 104.1 HV while the hardness of Al-6Si-5Cu alloy was increased to 118.2 HV. The ultimate tensile strength, yield strength and elongation to fracture of the thixoformed alloy which contained 3wt.% Cu were 241 MPa, 176 MPa and 3.2% respectively. The ultimate tensile strength, yield strength and elongation to fracture of the alloy that contained 6wt.% of Cu were 280 MPa, 238 MPa and 1.2% respectively. The fracture surface of the tensile sample with lower Cu content exhibited dimple rupture while higher Cu content showed a cleavage fracture.

scholarly journals A New Prediction Method for the Ultimate Tensile Strength of Steel Alloys with Small Punch Test

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1491 ◽  
Author(s):  
Jose Calaf Chica ◽  
Pedro Bravo Díez ◽  
Mónica Preciado Calzada
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Correlation Method ◽  
Small Punch Test ◽  
Steel Alloys ◽  
Small Punch ◽  
Punch Test ◽  
Hardening Coefficient

The load–deflection curve acquired from the Small Punch Test (SPT) is used to obtain the mechanical properties of materials using different correlation methods. The scattering level of these regressions tends to be high when a wide set of materials is analyzed. In this study, a correlation method based on a specific slope of the SPT curve was proposed to reduce scattering. Assuming the Ramberg–Osgood hardening law, the dependence of the SPT curve slope on the yield strength and the hardening coefficient is demonstrated by numerical simulations (FEM). Considering that the ultimate tensile strength could be obtained from the hardening coefficient, a response surface of the ultimate tensile strength with the yield strength and SPT curve slope, along with its equation, is presented for steel alloys. A summary of steel mechanical properties, based on the Boiler and Pressure Vessel Code (BPVC) and limited to yield strengths lower than 1300 MPa, is shown to select a set of experimental tests (tensile tests and SPTs) for which the range is completely covered. This experimental analysis validates the previous FEM analyses and the validity of the proposed correlation method, which shows more accurate correlations compared to the current methods.

Influence of Cold Rolling Reduction on Microstructure and Mechanical Properties in 204C2 Austenitic Stainless Steel

2019 ◽  
Vol 944 ◽  
pp. 193-198
Author(s):  
Tian Yi Wang ◽  
Ren Bo Song ◽  
Heng Jun Cai ◽  
Jian Wen ◽  
Yang Su
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Cold Rolling ◽  
Stainless Steels ◽  
Rolling Reduction ◽  
Cold Rolling Reduction

The present study investigated the effect of cold rolling reduction on microstructure and mechanical properties of a 204C2 Cr–Mn austenitic stainless steel which contained 16%Cr, 2%Ni, 9%Mn and 0.083 %C). The 204C2 austenitic stainless steels were cold rolled at multifarious thickness reductions of 10%, 20%, 30%,40% and 50%, which were compared with the solution-treated one. Microstructure of them was investigated by means of optical microscopy, X-ray diffraction technique and scanning electron microscopy. For mechanical properties investigations, hardness and tensile tests were carried out. Results shows that the cold rolling reduction induced the martensitic transformation (γ→α ́) in the structure of the austenitic stainless steel. With the increase of the rolling reduction, the amount of strain-induced martensite increased gradually. Hardness, ultimate tensile strength and yield strength increased with the incremental rolling reduction in 204C2 stainless steels, while the elongation decreased. At the thickness reduction of 50%, the specimen obtained best strength and hardness. Hardness of 204C2 stain steel reached 679HV. Ultimate tensile strength reached 1721 MPa. Yield strength reached 1496 MPa.

Effect of Mo and Bi on Mechanical Properties of Zr-Fe-Cr Alloy at Room Temperature

2013 ◽  
Author(s):  
B. F. Luan ◽  
L. Q. Yang ◽  
T. G. Wei ◽  
K. L. Murty ◽  
C. S. Long ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Microstructure Observation ◽  
Scanning Electron ◽  
Zr Alloy

To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.

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.

scholarly journals Tensile Strength and Creep Resistance in Nanocrystalline Cu, Pd and Ag

1990 ◽  
Vol 206 ◽  
Author(s):  
G. W. Nieman ◽  
J. R. Weertman ◽  
R. W. Siegel
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
True Strain ◽  
Constant Load ◽  
Creep Tests ◽  
Grain Sizes

ABSTRACTMeasurements of tensile strength and creep resistance have been made on bulk samples of nanocrystalline Cu, Pd and Ag consolidated from powders by cold compaction. Samples of Cu-Cu2O have also been tested. Yield strength for samples with mean grain sizes of 5–80 nm and bulk densities on the order of 95% of theoretical density are increased 2–5 times over that measured in pure, annealed samples of the same composition with micrometer grain sizes. Ductility in the nanocrystalline Cu has exceeded 6% true strain, however, nanocrystalline Pd samples were much less ductile. Constant load creep tests performed at room temperature at stresses of >100 MPa indicate logarithmic creep. The mechanical properties results are interpreted to be due to grain size-related strengthening and processing flaw-related weakening.

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.

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