Effects of Si Addition on Microstructure, Properties and Serration Behaviors of Lightweight Al-Mg-Zn-Cu Medium-entropy Alloys

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Yasong Li ◽  
Ruixuan Li ◽  
Yong Zhang

A series of as-cast lightweight multicomponent alloys Al(86-x)Mg10Zn2 Cu2 Six (x=0, 0.3, 0.6, 0.9, 1.2 at.%) were prepared by a vacuum induction furnace with a steel die. With the addition of Si, the reticular white Al-Cu phase deposited were gradually replaced by the gray eutectic Mg-Si phase, while the compressive strength of the alloys increases first and then decreases slowly. It is particularly noteworthy that the compression plasticity also exhibits this trend. When the Si content is 0.9 at.%, the compressive strength reaches its maximum at 779.11 MPa and the compressive plasticity reaches 20.91%. The effect of the addition of Si on the serration behavior of alloy was also studied; we found that the addition of Si introduces a new MgSi phase, and with the change of Si is significantly affects the morphology of the precipitated phase, which affects the serration behavior of the alloys. The comprehensive mechanical properties of the alloy are optimal at the critical point where the serration behavior disappears.In this work, we have provided a method and a composition for the preparation of a low-cost, high-strength, lightweight medium-entropy alloys.

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Yasong Li ◽  
Ruixuan Li ◽  
Yong Zhang

A series of as-cast lightweight multicomponent alloys Al(86-x)Mg10Zn2Cu2Six (x=0, 0.3, 0.6, 0.9, 1.2 at.%) were prepared by a vacuum induction furnace with a steel die. With the addition of Si, the reticular white Al-Cu phase deposited were gradually replaced by the gray eutectic Mg-Si phase, while the compressive strength of the alloys increases first and then decreases slowly. It is particularly noteworthy that the compression plasticity also exhibits this trend. When the Si content is 0.9 at.%, the compressive strength reaches its maximum at 779.11 MPa and the compressive plasticity reaches 20.91%. The effect of the addition of Si on the serration behavior of alloy was also studied; we found that the addition of Si introduces a new MgSi phase, and with the change of Si is significantly affects the morphology of the precipitated phase, which affects the serration behavior of the alloys. The comprehensive mechanical properties of the alloy are optimal at the critical point where the serration behavior disappears. In this work, we have provided a method and a composition for the preparation of a low-cost, high-strength, lightweight medium-entropy alloys.


2014 ◽  
Vol 936 ◽  
pp. 1229-1233
Author(s):  
Min Wang ◽  
Guang Xu ◽  
Zheng Liang Xue ◽  
Tao Xiong ◽  
Ming Xing Zhou

Two bearing steels, with higher Mn and Si content than GCr15, were refined in 50kg vacuum induction furnace followed by multi-pass rolling to 12mm thick flat on two-high mill. Mechanical properties and microstructures were measured and observed. The results show that higher content of Mn and Si decreases the martensite starting temperature (Ms), which is beneficial to the forming of martensite. The microstructure changes from martensite plus troostite to martensite, leading to higher hardness of steel and improvement of wear resistance. However, the band microstructure is easily formed by increase of Mn and Si, which is harmful to transverse property.


2012 ◽  
Vol 476-478 ◽  
pp. 188-193
Author(s):  
Jun Tian ◽  
Shun Xue ◽  
Guo Guang Cheng ◽  
Kuo Chih Chou

The mechanical properties and decarburization layer depths after heat treatment have been investigated for the experimental steels,which were melted by means of 10Kg vacuum induction furnace in the laboratory . It has been confirmed that additions of silicon and vanadium can improve strength of the steels and, the tensile strength of the steels increases with silicon content from 1.4% up to 2.0%. The reduction of carbon content and the addition of carbide forming elements decrease the decarburization sensitivity of the steels tested. The tensile strengths of the steels with carbon less than 0.5% are between 1016.88 to 1674.64 MPa, and the impact energy between 15.50 to 34.50 J, which are compared with the tensile strength of 1160.89MPa, the impact energy of 19.00 J for 55SiCrV. The steels with optimized compositions, which consists of 0.4~0.5% C, 1.6~2.0% Si, 0.8% Cr, 0.2% V, have a satisfactory property with high strength, high toughness and good anti-decarburization.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4223
Author(s):  
Po-Sung Chen ◽  
Yu-Chin Liao ◽  
Yen-Ting Lin ◽  
Pei-Hua Tsai ◽  
Jason S. C. Jang ◽  
...  

Most high-entropy alloys and medium-entropy alloys (MEAs) possess outstanding mechanical properties. In this study, a series of lightweight nonequiatomic Al50–Ti–Cr–Mn–V MEAs with a dual phase were produced through arc melting and drop casting. These cast alloys were composed of body-centered cubic and face-centered cubic phases. The density of all investigated MEAs was less than 5 g/cm3 in order to meet energy and transportation industry requirements. The effect of each element on the microstructure evolution and mechanical properties of these MEAs was investigated. All the MEAs demonstrated outstanding compressive strength, with no fractures observed after a compressive strain of 20%. Following the fine-tuning of the alloy composition, the Al50Ti20Cr10Mn15V5 MEA exhibited the most compressive strength (~1800 MPa) and ductility (~34%). A significant improvement in the mechanical compressive properties was achieved (strength of ~2000 MPa, strain of ~40%) after annealing (at 1000 °C for 0.5 h) and oil-quenching. With its extremely high specific compressive strength (452 MPa·g/cm3) and ductility, the lightweight Al50Ti20Cr10Mn15V5 MEA demonstrates good potential for energy or transportation applications in the future.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.


2010 ◽  
Vol 168-170 ◽  
pp. 564-569
Author(s):  
Guang Lin Yuan ◽  
Jing Wei Zhang ◽  
Jian Wen Chen ◽  
Dan Yu Zhu

This paper makes an experimental study of mechanical properties of high-strength pumpcrete under fire, and the effects of heating rate, heating temperature and cooling mode on the residual compressive strength(RCS) of high-strength pumpcrete are investigated. The results show that under air cooling, the strength deterioration speed of high-strength concrete after high temperature increases with the increase of concrete strength grade. Also, the higher heating temperature is, the lower residual compressive strength value is. At the same heating rate (10°C/min), the residual compressive strength of C45 concrete after water cooling is a little higher than that after air cooling; but the test results are just the opposite for C55 and C65 concrete. The strength deterioration speed of high-strength concrete after high temperature increases with the increase of heating rate, but not in proportion. And when the heating temperature rises up between 200°C and 500°C, heating rate has the most remarkable effect on the residual compressive strength of concrete. These test results provide scientific proofs for further evaluation and analysis of mechanical properties of reinforced-concrete after exposure to high temperatures.


Author(s):  
Muhammad Armaghan Siffat ◽  
Muhammad Ishfaq ◽  
Afaq Ahmad ◽  
Khalil Ur Rehman ◽  
Fawad Ahmad

This study is supervised to assess the characteristics of the locally available wheat straw ash (WSA) to consume as a substitute to the cement and support in enhancing the mechanical properties of concrete. Initially, after incineration at optimum temperature of 800°C for 0.5, the ash of wheat straw was made up to the desirable level of fineness by passing through it to the several grinding cycles. Subsequently, the X-ray fluorescence (XRF) along with X-ray diffraction (XRD) testing conducted on ash of wheat straw for the evaluation its pozzolanic potential. Finally, the specimens of concrete were made by consuming 10% and 20% percentages of wheat straw ash as a replacement in concrete to conclude its impact on the compressive strength of high strength concrete. The cylinders of steel of dimensions 10cm diameter x 20cm depth were acquired to evaluate the compressive strength of high strength concrete. The relative outcomes of cylinders made of wheat straw ash substitution presented the slight increase in strength values of the concrete. Ultimately, the C-100 blends and WSA aided cement blends were inspected for the rheology of WSA through FTIR spectroscopy along with Thermogravimetric technique. The conclusions authenticate the WSA potential to replace cement in the manufacturing of the high strength concrete.


This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.


2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.


2018 ◽  
Vol 25 (6) ◽  
pp. 1039-1058 ◽  
Author(s):  
Sumit Das Lala ◽  
Ashish B. Deoghare ◽  
Sushovan Chatterjee

AbstractThe inherent properties of bio-composites such as biodegradability, environment friendly, low cost of production, high strength and durability make them a suitable replacement to traditional materials such as glass and nylon. Bio-polymers are finding wide applications due to their intrinsic properties such as low density, low thermal conductivity, corrosion resistance and ease of manufacturing complex shapes. This paper aims toward a comprehensive study on polymer bio-composites. The review mainly focuses on types of reinforcements such as natural fibers, seed shells, animal fibers, cellulose, bio-polymers, bio-chemicals and bioceramics which enhance the mechanical properties, such as tensile strength, compressive strength, flexural strength, Young’s modulus and creep behavior, of the composites. The pertinent study carried out in this review explores an enormous potentiality of the composites toward a wide variety of applications.


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