CHEMICAL DEPOLYMERIZATION OF WASTE PLASTICS IN BUBBLE COLIUMN REACTOR FOR BLENDED FABRICATION

The degradation of waste plastics in the environment is such an essential issue for Earth protection. This study indicated the importance of using waste bottles to produce recycled depolymerization Polyethylene Terephthalate (DPET). The bubble column reactor technique and its effect in the depolymerization process have been investigated. The DPET with Poly-methyl methacrylate (PMMA) has been used to fabricate the hybrid polymer to improve the mechanical properties. Thus, different percentages (1, 2, 3, 5, and 10 %) of (DPET) are used to surmise its repercussions on the mechanical properties of the polymer. These ramifications were studied through a sequence of research laboratory tests, including tensile strength, Charpy impact, and shore-D hardness, and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The results show a development interest, especially for impact strength and surface hardness, where both tests show compatible results, especially at (10%) of DPET. At the same time, maximum results of tensile strength are at (3%). FTIR analysis shows a chemical reaction between DPET and PMMA, which significantly improves the characteristics and makes it a wide range of available applications.

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Improving the surface quality and mechanical properties of selective laser sintered PA2200 components by the vibratory surface finishing process

SN Applied Sciences ◽

10.1007/s42452-021-04371-4 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

Hamaid M. Khan ◽

Tolga B. Sirin ◽

Gurkan Tarakci ◽

Mustafa E. Bulduk ◽

Mert Coskun ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Roughness ◽

Tensile Strength ◽

Additive Manufacturing ◽

Microstructural Analysis ◽

Surface Hardness ◽

Physical And Mechanical Properties ◽

Surface Finishing ◽

Finishing Process ◽

Wide Range

Abstract This paper attempts to improve the physical and mechanical properties of selective laser sintered polyamide PA2200 components through a vibratory surface finishing process by inducing severe plastic deformation at the outer surface layers. The industrial target of additive manufacturing components is to obtain structures having surface roughness, hardness, and other mechanical properties equivalent to or better than those produced conventionally. Compared to the as-built SLS PA2200 samples, vibratory surface finishing treated specimens exhibited a smooth surface microstructure and more favorable roughness, hardness, and tensile strength. Also, the duration of the vibratory surface finishing process showed a further improvement in the surface roughness and hardness of the SLS samples. Compared to the as-built state, the roughness and hardness of the surface-treated samples improved by almost 90% and 15%, respectively. Consequently, microstructural analysis indicates that lower surface roughness and enhanced surface hardness is a crucial factor in influencing the overall tensile strength of SLS-PA2200 components. We consider that the combination of VSF and SLS processes can successfully handle a wide range of potential applications. This study also highlights the efficiency and applicability of the vibratory surface finishing process to other additive manufacturing processes and materials. Graphic abstract

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Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

Mustansiria Dental Journal ◽

10.32828/mdj.v14i1.768 ◽

2019 ◽

Vol 14 (1) ◽

pp. 110

Author(s):

Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽

Dr. Firas Abd K. Abd K.

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Silver Nitrate ◽

Surface Hardness ◽

Mechanical Tests ◽

Hardness Tester ◽

Acrylic Resins ◽

The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

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Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

Metals ◽

10.3390/met11040548 ◽

2021 ◽

Vol 11 (4) ◽

pp. 548 ◽

Cited By ~ 1

Author(s):

Leonid Agureev ◽

Valeriy Kostikov ◽

Zhanna Eremeeva ◽

Svetlana Savushkina ◽

Boris Ivanov ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Strength Properties ◽

Alumina Nanoparticles ◽

Metal Powders ◽

Wide Range ◽

The Matrix ◽

Spark Plasma ◽

Average Size

The article presents the study of alumina nanoparticles’ (nanofibers) concentration effect on the strength properties of pure nickel. The samples were obtained by spark plasma sintering of previously mechanically activated metal powders. The dependence of the grain size and the relative density of compacts on the number of nanofibers was investigated. It was found that with an increase in the concentration of nanofibers, the average size of the matrix particles decreased. The effects of the nanoparticle concentration (0.01–0.1 wt.%) on the elastic modulus and tensile strength were determined for materials at 25 °C, 400 °C, and 750 °C. It was shown that with an increase in the concentration of nanofibers, a 10–40% increase in the elastic modulus and ultimate tensile strength occurred. A comparison of the mechanical properties of nickel in a wide range of temperatures, obtained in this work with materials made by various technologies, is carried out. A description of nanofibers’ mechanisms of influence on the structure and mechanical properties of nickel is given. The possible impact of impurity phases on the properties of nickel is estimated. The tendency of changes in the mechanical properties of nickel, depending on the concentration of nanofibers, is shown.

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Dependence of Microstructures and Mechanical Properties on the Growth Rate and Composition in Directionally Solidified Mg-Gd Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.327.82 ◽

2022 ◽

Vol 327 ◽

pp. 82-97

Author(s):

He Qin ◽

Guang Yu Yang ◽

Shi Feng Luo ◽

Tong Bai ◽

Wan Qi Jie

Keyword(s):

Mechanical Properties ◽

Growth Rate ◽

Tensile Strength ◽

Ultimate Tensile Strength ◽

Dendritic Structure ◽

Directionally Solidified ◽

Dendrite Morphology ◽

Microstructural Parameters ◽

Wide Range ◽

Microstructures And Mechanical Properties

Microstructures and mechanical properties of directionally solidified Mg-xGd (5.21, 7.96 and 9.58 wt.%) alloys were investigated at a wide range of growth rates (V = 10-200 μm/s) under the constant temperature gradient (G = 30 K/mm). The results showed that when the growth rate was 10 μm/s, different interface morphologies were observed in three tested alloys: cellular morphology for Mg-5.21Gd alloy, a mixed morphology of cellular structure and dendritic structure for Mg-7.96Gd alloy and dendrite morphology for Mg-9.58Gd alloy, respectively. Upon further increasing the growth rate, only dendrite morphology was exhibited in all experimental alloys. The microstructural parameters (λ1, λ2) decreased with increasing the growth rate for all the experimental alloy, and the measured λ1 and λ2 values were in good agreement with Trivedi model and Kattamis-Flemings model, respectively. Vickers hardness and the ultimate tensile strength increased with the increase of the growth rate and Gd content, while the elongation decreased gradually. Furthermore, the relationships between the hardness, ultimate tensile strength, the growth rate and the microstructural parameters were discussed and compared with the previous experimental results.

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Correlation between Porosity and Electrical-Mechanical Properties of Carbon Nanotube Buckypaper with Various Porosities

Journal of Nanomaterials ◽

10.1155/2015/945091 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Ling Liu ◽

Qiaoxin Yang ◽

Jingwen Shen

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Carbon Nanotube ◽

The Other ◽

Positive Pressure ◽

Filtration Method ◽

Elongation At Break ◽

Conductive Materials ◽

Wide Range ◽

Electrical Conductivities

Porous carbon nanotube (CNT) buckypapers (BPs) with various porosities were obtained by using a positive pressure filtration method. The porosity of the BPs fell into a wide range of 11.3–39.3%. Electrical conductivities and tensile mechanical properties of the prepared BPs were then measured and correlated with the porosity of the CNT BPs. Results demonstrated that the conductivities, tensile strength, and elastic modulus of the BPs could decrease by increasing their porosity. The elongation at break of the BPs on the other hand did increase significantly, suggesting improved toughness of the BPs. The obtained electrical conductivity and tensile strength of the porous BPs can reach nearly 0.6 S/m and 26 MPa, respectively, which may be potentially useful in composites reinforcement and conductive materials.

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Hybrid Composites Based on Polypropylene with Basalt/Hazelnut Shell Fillers: The Influence of Temperature, Thermal Aging, and Water Absorption on Mechanical Properties

Polymers ◽

10.3390/polym12010018 ◽

2019 ◽

Vol 12 (1) ◽

pp. 18 ◽

Cited By ~ 2

Author(s):

Anna Kufel ◽

Stanisław Kuciel

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Water Absorption ◽

Thermal Aging ◽

Hybrid Composites ◽

Coefficient Of Thermal Expansion ◽

Tensile Modulus ◽

Charpy Impact ◽

Creep Tests ◽

Influence Of Temperature

The aim of the research was to study the effects of adding natural fillers to a polypropylene (PP) matrix on mechanical and physical properties of hybrid composites. The 10%, 15%, and 20% by weight basalt fibers (BF) and ground hazelnut shells (HS) were added to the PP matrix. Composites were produced by making use of an injection molding method. Tensile strength, tensile modulus, strain at break, Charpy impact strength, and the coefficient of thermal expansion were determined. The influence of temperature, thermal aging, and water absorption on mechanical properties was also investigated. In addition, short-time creep tests were carried out. To characterize the morphology and the filler distribution within the matrix, a scanning electron microscope (SEM) was used. The results showed that the addition of the two types of filler enhanced mechanical properties. Furthermore, improvements in thermal stability were monitored. After water absorption, the changes in the tensile properties of the tested composites were moderate. However, thermal aging caused a decrease in tensile strength and tensile modulus.

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The Effect of Scandium on the Mechanical Properties of A356 Aluminium Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.707.144 ◽

2016 ◽

Vol 707 ◽

pp. 144-147

Author(s):

Ying Pio Lim ◽

Wei Hong Yeo ◽

A. Masita

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Aluminium Alloy ◽

Die Casting ◽

A356 Alloy ◽

Charpy Impact ◽

Casting Process ◽

Die Casting Process ◽

Charpy Impact Strength ◽

A356 Aluminium Alloy

In this project, the addition of scandium (Sc) into A356 aluminium alloy was studied for its effect on the mechanical properties after gravity die casting process. Scandium addition was administered at the weight percentages of 0.1, 0.2 and 0.3. The results obtained in this work revealed that scandium can significantly enhance the mechanical properties of A356 alloy in terms of tensile strength, hardness and charpy impact strength. In general, the addition of 0.2 wt% Sc in A356 alloy was found to be able to achieve the maximum tensile strength of 172.94MPa as compared to 136.03MPa for sample without Sc. No significant improvement in tensile strength was found when more than 0.3wt% added to the alloy. As for hardness, the sample with 0.3 wt% Sc attained the maximum Vicker’s hardness of 86.60 HV as compared to 76.48 HV for unmodified A356. Similarly, the addition of 0.3wt% Sc in A356 can achieve highest impact energy of 2.71J as compare to 1.09J for unmodified A356.

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The Effect of the Compression on the Mechanical Properties of Wood Material

Materials Science Forum ◽

10.4028/www.scientific.net/msf.537-538.41 ◽

2007 ◽

Vol 537-538 ◽

pp. 41-46 ◽

Cited By ~ 1

Author(s):

László Kuzsella ◽

Imre Szabó

Keyword(s):

Mechanical Properties ◽

Charpy Impact ◽

Charpy Impact Test ◽

Bending Test ◽

Wood Material ◽

Ordinary Life ◽

Three Point Bending ◽

Wide Range ◽

New Process ◽

New Applications

The wood is one of the most favourable structural material. It appears on all fields of the ordinary life. It is difficult to say an application where the wood is not used due to its cheap price, availability and just simply the beauty. Beside of the wide range of process technologies a new process appeared. This process changes the properties of the material and brings many new applications to this traditional material. This process is the compression of the structural wood material. This publication deals with the effect of the compression on the mechanical properties of two hardwoods (beech: fagus sylvatica, oak: quercus) by the help of the three-point bending test and the Charpy impact test.

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Experimental Research and Analysis of Non-alloy Structural Steel Response Exposed to High Temperature Conditions

High Temperature Materials and Processes ◽

10.1515/htmp-2012-0108 ◽

2013 ◽

Vol 32 (2) ◽

pp. 163-169

Author(s):

Josip Brnic ◽

Goran Turkalj ◽

Sanjin Krscanski

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Tensile Strength ◽

Structural Steel ◽

Impact Energy ◽

Charpy Impact ◽

Experimental Results ◽

Charpy Impact Energy ◽

Over Time

AbstractThis paper presents and analyzes the responses of non-alloy structural steel (1.0044) subjected to uniaxial stresses at high temperatures. This research has two important determinants. The first one is determination of stress-strain dependence and the second is monitoring the behavior of materials subjected to a constant stress at constant temperature over time. Experimental results refer to mechanical properties, elastic modulus, total elongations, creep resistance and Charpy V-notch impact energy. Experimental results show that the tensile strength and yield strength of the considered material fall when the temperature rises over 523 K. Significant decrease in value is especially noticeable when the temperature rises over 723 K. In addition, engineering assessment of fracture toughness was made on the basis of Charpy impact energy. It is visible that when temperature raises then impact energy increases very slightly.

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Influence of normalizing post carburizing treatment on microstructure, mechanical properties and fracture behavior of low alloy gear steels

AIMS Materials Science ◽

10.3934/matersci.2021051 ◽

2021 ◽

Vol 8 (5) ◽

pp. 836-851

Author(s):

Hiremath Pavan ◽

◽

M. C. Gowrishankar ◽

Shettar Manjunath ◽

Sharma Sathyashankara ◽

...

Keyword(s):

Mechanical Properties ◽

Impact Resistance ◽

Charpy Impact ◽

Carbon Steels ◽

Mode Analysis ◽

Low Carbon ◽

The Core ◽

Wide Range ◽

Before And After ◽

Fine Pearlite

<abstract> <p>Steel is a versatile metal, got a wide range of applications in all the fields of engineering and technology. Generally, low carbon steels are tough and high alloy carbon steels are hard in nature. Certain applications demand both properties in the same steel. Carburization is one such technique that develops hard and wear resistant surfaces with a soft core. The objective of this work is to study the influence of post carburizing treatment (normalizing) on three grades of steels (EN 3, 20MnCr5, and EN 353). Post carburizing treatments are necessary to overcome the adverse effects of carburization alone. Here carburization was carried out in the propane atmosphere by heating the gas carburizing furnace to 930 ℃ for more than a day. Normalizing was carried out at 870 ℃ for 1 h and cooled in air. Tensile, hardness, Charpy impact tests along with SEM (scanning electron microscopy) and EDAX (energy dispersive X-ray analysis) were conducted to analyze the phase transformation, failure mode analysis in all the samples. Carburized steels displayed the formation of ferrite, pearlite, and sometimes bainite phases in the core and complete coarse pearlite in the case regions, whereas in the post carburized steels, increased amount of ferrite, fine pearlite, and bainite in the core and fine pearlite with traces of bainite in the case region was observed. Normalizing also refines the grain with increased UTS (ultimate tensile strength), hardness, and impact resistance. EN 353 showed higher UTS among the steels with 898 MPa after carburization and 1370 MPa after normalizing treatment. Maximum hardness of 48 HRC was observed in 20MnCr5 and toughness was superior in EN 3 with energy absorbed during test i.e., 8 and 12 J before and after normalizing treatment. Based on the fracture surface analysis, in EN 353 steel, a finer array of dimples with voids and elongated bigger clustered dimples containing ultrafine dimples array are observed in the core and case respectively during carburizing whereas, more density of river pattern and cleavage failure (brittle) are observed in the core and case respectively after post carburizing (normalizing) treatment. There is a reduction in the ductility of the steels after post carburizing treatment. It was observed that normalizing treatment produces superior mechanical properties in the carburized steels by grain refinement and strong microstructures like bainite. Normalizing as post carburizing treatment can be recommended for engineering applications where ductile core and hard surface are of great importance.</p> </abstract>

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