scholarly journals Enhanced Strength and Plasticity of CoCrNiAl0.1Si0.1 Medium Entropy Alloy via Deformation Twinning and Microband at Cryogenic Temperature

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7574
Author(s):  
Xiao-Hua Gu ◽  
Yu-Quan Meng ◽  
Hui Chang ◽  
Tian-Xiang Bai ◽  
Sheng-Guo Ma ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Cryogenic Temperature ◽  
Melting Furnace ◽  
Deformation Mechanisms ◽  
Deformation Twins ◽  
Peierls Barrier ◽  
Lattice Distortions ◽  
Multiple Deformation

The synthesis of lightweight yet strong-ductile materials has been an imperative challenge in alloy design. In this study, the CoCrNi-based medium-entropy alloys (MEAs) with added Al and Si were manufactured by vacuum arc melting furnace subsequently followed by cool rolling and anneal process. The mechanical responses of CoCrNiAl0.1Si0.1 MEAs under quasi-static (1 × 10−3 s−1) tensile strength showed that MEAs had an outstanding balance of yield strength, ultimate tensile strength, and elongation. The yield strength, ultimate tensile strength, and elongation were increased from 480 MPa, 900 MPa, and 58% at 298 K to 700 MPa, 1250 MPa, and 72% at 77 K, respectively. Temperature dependencies of the yield strength and strain hardening were investigated to understand the excellent mechanical performance, considering the contribution of lattice distortions, deformation twins, and microbands. Severe lattice distortions were determined to play a predominant role in the temperature-dependent yield stress. The Peierls barrier height increased with decreasing temperature, owing to thermal vibrations causing the effective width of a dislocation core to decrease. Through the thermodynamic formula, the stacking fault energies were calculated to be 14.12 mJ/m2 and 8.32 mJ/m2 at 298 K and 77 K, respectively. In conclusion, the enhanced strength and ductility at cryogenic temperature can be attributed to multiple deformation mechanisms including dislocations, extensive deformation twins, and microbands. The synergistic effect of multiple deformation mechanisms lead to the outstanding mechanical properties of the alloy at room and cryogenic temperature.

Effect on the Mechanical Properties of Aluminum-Based Hybrid Metal Matrix Composite Using Stir Casting Method

2019 ◽  
Vol 969 ◽  
pp. 253-259 ◽  
Author(s):  
Ravi Butola ◽  
Chandra Pratap ◽  
Anurag Shukla ◽  
Ravinder S. Walia
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Automobile Industry ◽  
Metal Matrix ◽  
Weight Ratio ◽  
Melting Furnace ◽  
Stir Casting ◽  
Free Atmosphere ◽  
Percentage Elongation

Al based-Hybrid Metal Matrix Composites (HMMC) are becoming widely popular in the Automobile industry due to its highly attractive characteristics of enhanced hardness. The heterogeneous mixture formed due to the presence of reinforcement particles adds to the strength, wear resistance, hardness etc. to the specimen. In this research, fine ashes of bagasse (sugarcane), banana, and jute (coconut covering) were used, produced by burning the above in free atmosphere. The sample was sieve tested to 200 mesh size and ball milled in the presence of SiC with weight ratio of 1:2. Stir casting of the composite was performed in the melting furnace to produce different specimens of Al6061 consisting of different types of reinforcement. The specimens were then exposed to various tests to determine Ultimate tensile strength, yield strength, hardness, and percentage elongation. The best results termed out with the specimen reinforced with banana ash at the cost of loss in ductility exhibiting Ultimate tensile strength 115.4 MPa, Yield Strength 76.4 MPa, Vickers hardness 55-77 HV and Percentage elongation 21%.

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 STUDY OF THE EFFECT OF TiB2 PARTICLES ON THE STRUCTURE, DEFORMATION BEHAVIOR, AND PROPERTIES OF THE ALUMINUM ALLOY 1550

2020 ◽  
pp. 102-116
Author(s):  
Aleksandr B. VOROZHTSOV ◽  
◽  
Vladimir V. PLATOV ◽  
Aleksandr A. KOZULIN ◽  
Anton P. KHRUSTALEV ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Relative Elongation ◽  
Rolling Direction ◽  
Strength Properties ◽  
Rolled Sheet ◽  
Master Alloys ◽  
Cast Alloys ◽  
Tib2 Particles

In this work, the special master alloys containing aluminum and TiB2 powder with bimodal particle size distribution in three mixture compositions are prepared. The master alloys are infused into the melts using an external ultrasound source. The castings with particles had smaller grain sizes than the initial castings without particles. It is found that the hardness, yield strength, and ultimate tensile strength reach higher values with an increase in the relative elongation of the cast alloys with added particles. A warm rolling mode is employed for the studied alloys to obtain sheet blanks. It is shown that the staged shrinkage of the billets up to deformation of 80 % with periodic heating up to 300 °C allows one to obtain defect-free sheet products. The structure of the rolled sheet-alloys is characterized by the plate-shaped grains elongated along the rolling direction with pockets of submicron-sized grains in between. The strength properties of the studied rolled alloys exceeded those of the cast alloys. In the case of the rolled alloys, an increase in the yield strength, ultimate tensile strength, and ductility is revealed for the alloys with particles as compared to the ones with no particles added.

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

scholarly journals Development of High Performance (Mechanical and Wear Properties) of AA 6061-Hybrid Nano Composites Via Liquid Metallurgy Route

2019 ◽  
Vol 22 (2) ◽  
pp. 143-150
Author(s):  
Hussain J. M. Al-Alkawi ◽  
Abduljabbar Owaid Hanfesh ◽  
Saja Mohammed Noori Mohammed Rauof
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Wear Rate ◽  
Yield Strength ◽  
Base Metal ◽  
Young Modulus ◽  
Nano Particles ◽  
Wear Properties ◽  
Constant Weight ◽  
Weight Percentage

This research is devoted to study the influence of different weight percent concerning to the additions of Ti and Cu on mechanical and tribological properties of AA6061. The composite materials consist of different weight percentage of Ti (0.2, 0.4, and 0.6) wt% and constant weight percentage of Cu (0.2) wt% which were fabricated by liquid metallurgy route technique. Microstructural characterization and phases have been examined by using SEM (scanning electron microscopic).SEM examination showed uniform distribution of nano Ti and Cu in AA6061. The consequences of mechanical tests demonstrated clear enhancement in mechanical properties, such as ultimate tensile strength, yield strength, young modulus, ductility% and hardness at additive percentage of 0.4% Ti+0.2%Cu nano particles incorporated into molten AA6061. Percentage of enhancement ultimate tensile strength is about 73.3%, yield strength about 82.7%, young modulus is about 21.2%, the  Vickers hardness about 42.6% and the decreasing in ductility was about 25.2% compared with the metal matrix (AA6061). The wear rate test was performed by using pin on disc rig for both hybrid nano composite and base metal (AA6061) under various loads (10,15and 20) N with sliding speed (1.282) m/sec at a (10) min’s time. The results showed a decrease in wear rate at 0.4%Ti+0.2%Cu compared with the base metal (AA6061). Improvement percentage of wear rate is about 105% at 20 N load.

scholarly journals Processing and Property Evaluation of Nano Al2O3 Reinforced Copper- 5% Tin Composites for Bearing Applications

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1027-1032
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Copper Matrix ◽  
Matrix Composites ◽  
Wear Properties ◽  
Casting Technique ◽  
Tin Metal

Nano technology has fascinated the attention of numerous material scientists and design engineers. The nano scaled particulates incorporation exhibit many attractive and special properties. The inclusion of nano particulates into the copper matrix might augments the hardness, ultimate tensile strength and yield strength significantly increases, maintaining the ductility. In this paper, the nano Al2O3 reinforced copper - 5%tin- metal matrix composites were manufactured by stir casting technique and reinforcement is varied from 0wt. % to 9wt. % in ventures of 3wt. %. The nano composites are characterized in terms of their mechanical and wear properties. Results revealed that, the distribution of nano Al2O3 particulates is fairly uniform in copper - 5%tin metal matrix. As the level of reinforcement increases, hardness, yield strength, ultimate tensile strength, and wear resistance of the copper - 5%tin – nano Al2O3 metal matrix composites increases. The developed nano metal matrix composites may be an alternative material for bearing applications

Tensile Properties and Fracture Behavior of SiCp/AC4CH Composite at Loading Velocities of up to 10m/s

2004 ◽  
Vol 449-452 ◽  
pp. 305-308
Author(s):  
Lei Wang ◽  
Toshiro Kobayashi ◽  
Chun Ming Liu
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Tensile Test ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Tensile Deformation ◽  
Optical Microscope ◽  
Fracture Elongation ◽  
Before And After

Tensile test at loading velocities up to 10 m·s-1(strain rate up to 3.2x102s-1) was carried out forr SiCp/AC4CH composite and AC4CH alloy. The microstructure of the composite before and after tensile deformation was carefully examined with both optical microscope and SEM. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increase with increasing loading velocity up to 10 m·s-1. Comparing with AC4CH alloy, the fracture elongation of the composite is sensitivity with the increasing strain rate. The YS of both the composite and AC4CH alloy shows more sensitive than that of the UTS with the increasing strain rate, especially in the range of strain rate higher than 102s-1.

Aging Response Curves

2004 ◽  
pp. 133-173
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Casting Alloy ◽  
Response Curves ◽  
Data Set ◽  
Casting Alloys ◽  
Aging Response ◽  
Wide Range

Abstract This data set presents aging response curves for a wide range of aluminum casting alloys. The aging response curves are of two types: room-temperature, or "natural," curves and artificial, or "high-temperature," curves. The curves in each group are presented in the numeric sequence of the casting alloy designation. The curves included are the results of measurements on individual lots considered representative of the respective alloys and tempers. The properties considered are yield strength, ultimate tensile strength, elongation, and Brinell hardness.

Effect of Grain Size on Microstructure and Orientation of Fe-25Mn-3Si-3Al Steel

2015 ◽  
Vol 1095 ◽  
pp. 107-110
Author(s):  
Yong Juan Dai ◽  
Jian Gang Wang ◽  
Hao En Mao ◽  
Zhen Li Mi ◽  
Chi Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Twip Steel ◽  
Annealing Twin ◽  
Deformation Twins

The typical Fe-25Mn-3Si-3Al TWIP steel with different microstructure scale were investigated. It was found When the grains size is up to 35μm in the 25Mn-3Si-3Al TWIP steel samples, the twinning induced plasticity (TWIP) effect can fully developed and results in above 80% elongation. grain size had a strong effect on the mechanical properties. It was concluded that with increasing grain size ultimate tensile strength decreases, while elongation increases obviously.The annealing twin has the twin’s orientation, during deformation the annealing twin has get orientation ready for deformation twins

Sign in / Sign up

Export Citation Format

Share Document