scholarly journals Electro mechanical properties changes of LDPE doped with industrial type MgO for cable insulation purposes

Author(s):  
Sherif Haggag ◽  
Loai Nasrat ◽  
Hanafy Ismail

<p>This manuscript introduces the changes of a comprehensive electromechanical properties bundle for low density polyethylene compounded to microscale magnesia (LDPE/MgO) to obtain electrical cables insulating material. Composites of various filler loading weight ratios were prepared by melt intercalation technique; multiple samples were produced in sets as they were cut with definite dimensions as per recommendations of the related testing standard then electrically and mechanically examined following the instruction dictated by the code while preserving typical test condition for all sets. Dielectric strength, volume resistivity, capacitance, and loss angle were the tests of the electrical test pack, while elongation, tensile strength, and melt flow rate were the mechanical and rheological tests applied. Test’s findings were compared to each other’s and to the base material to identify the differentiation. Electrical test results show improvements in the composite features at low loading percentages, whereas the mechanical tests revealed a deterioration in the mechanical properties along with all ratios under investigation. The research aims to determine the compositing benefit extents and drawbacks when a conventional compounding method and inexpensive filler are used, incurring marginal cost impact.</p>

2020 ◽  
Vol 15 (3) ◽  
pp. 44-49
Author(s):  
Ibiyemi A. Idowu ◽  
Olutosin O. Ilori

The study examined the effect of fillers on the mechanical properties of the recycled low density polyethylene composites under weathered condition with a view of managing the generation and disposal of plastic wastes. Discarded pure water sachets and fillers (glass and talc) were sourced and recycled. Recycled low density polyethylene (RLDPE) and preparation of RLDPE/glass, RLDPE/talc and RLDPE/glass/talc composites were carried out using a furnace at compositions of 0 – 40% in steps of 10% by weight. The mixtures were poured into hand-laid mould. The samples produced were exposed to sunlight for eight (8) weeks and their mechanical properties were studied. The results of mechanical tests revealed that tensile strength decreased with increasing filler loading while impact strength and hardness property increased marginally and considerably with increasing filler loading for all the composites respectively. The study concluded that glass and talc were able to reinforce recycled low density polyethylene under weathered condition. Keywords: Recycled Low Density Polyethylene (RLDPE); Fillers; Glass, Talc; Weathering condition; Sunlight; and Mechanical properties; Tensile strength, Impact and hardness


2010 ◽  
Vol 37-38 ◽  
pp. 1092-1100
Author(s):  
Ji Bin Li ◽  
Ke Ke Xu ◽  
Xin Bo Lin ◽  
Xiao Yu Wu ◽  
Guo Li Gao

In this paper, ultrasonic vibration is adopted and exerted on injection molding in order to improve plastics’ forming ability, and the impact testing is used to analyze different injection parts’ mechanical properties. On the one hand, experiments prove that ultrasonic vibration can increase polymer’s melt flow rate, decrease melt viscosity, and improve injection flowing in mould cavity. On the other hand, the mechanical tests prove that the ultrasonic vibration can improve plastics’ tensile strength, elastic modulus and other mechanical properties. As a result, a weldless ultrasound-assisted injection molding method is recommended.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
F. Mirjalili ◽  
L. Chuah ◽  
E. Salahi

A nanocomposite containing polypropylene (PP) and nanoα-Al2O3particles was prepared using a Haake internal mixer. Mechanical tests, such as tensile and flexural tests, showed that mechanical properties of the composite were enhanced by addition of nanoα-Al2O3particles and dispersant agent to the polymer. Tensile strength was approximately∼16% higher than pure PP by increasing the nanoα-Al2O3loading from 1 to 4 wt% into the PP matrix. The results of flexural analysis indicated that the maximum values of flexural strength and flexural modulus for nanocomposite without dispersant were 50.5 and 1954 MPa and for nanocomposite with dispersant were 55.88 MPa and 2818 MPa, respectively. However, higher concentration of nanoα-Al2O3loading resulted in reduction of those mechanical properties that could be due to agglomeration of nanoα-Al2O3particles. Transmission and scanning electron microscopic observations of the nanocomposites also showed that fracture surface became rougher by increasing the content of filler loading from 1 to 4% wt.


Author(s):  
German Cota-Sanchez ◽  
Lin Xiao

Abstract Inconel 625 is considered one of the candidate materials for reactor fuel cladding in the Canadian supercritical water reactor (SCWR) design. Gas tungsten arc welding (GTAW) is being evaluated as a joining technique for SCWR fuel cladding since this method is widely used to join components in the power and nuclear industry. During the GTAW process, the welding thermal cycle produces different types of microstructures in both the heat-affected zone (HAZ) and fusion zone (FZ) that affect the material's mechanical properties. A series of welding experiments at various weld conditions were performed using an automatic GTAW orbital process on Inconel 625 alloy tubing. Simple analytical heat conduction and grain growth models were developed to predict weld temperature profiles and metallurgical transformations. Weld characterization included mechanical tests, optical microscopy, scanning electron microscopy - energy dispersive spectroscopy (SEM-EDS) elemental analysis, and microhardness measurements. Weld microstructural characterization revealed that a characteristic dendritic structure was formed in the FZ, while the HAZ exhibited larger equiaxed grains than those found in the base material. SEM-EDS analysis showed no distinct alloying element segregation in both the HAZ and FZ. Welds produced with heat inputs of about 3.00 kJ/cm3 presented similar mechanical properties as those observed in the base material. In these welds, grain growth was homogenously minimized in the FZ. It is concluded that the effective welding heat input control can optimize the weld microstructure and the weld mechanical properties in Inconel 625 tubing used as Canadian SCWR reactor fuel cladding.


2011 ◽  
Vol 24 (6) ◽  
pp. 755-766 ◽  
Author(s):  
S. Joseph ◽  
V.A. Bambole ◽  
P.A. Mahanwar

Carbon nanoplatelet and nanoalumina reinforced PEEK nanocomposites were fabricated by twin-screw extrusion followed by injection molding. The effect of the filler loading on mechanical properties, morphology, dielectric strength, and thermal stability of the composites has been analyzed. The mechanical properties were found to increase with nanoplatelet content up to 1% loading (optimum filler content) and after that, due to agglomeration of filler, slight decrease in properties were observed. For alumina-filled systems mechanical properties increased with increasing filler content due to the well-dispersed fillers in the composites. The modulus and toughness of alumina-filled composites were higher than platelet-filled composites.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 202
Author(s):  
Javier de Prado ◽  
María Sánchez ◽  
David Swan ◽  
Alejandro Ureña

The determination of the mechanical properties of a brazed joint is an important factor to reach the metallurgical level of a joint development. This paper evaluates the mechanical properties, and its correlation with the joint microstructure, of a W-CuCrZr joint brazed in a high vacuum furnace using 80Cu-20Ti flexible filler material in tape form. This joint is meant to be implemented in the divertor application in future fusion power plants. Main experimental parameters were a brazing temperature of 960 °C and a dwell time of 10 min. The microstructure of the joint was constituted by Cu solid solution and Cu4Ti phases. This last phase was distributed in the W-braze interface. Mechanical properties were evaluated by means of Vickers microhardness and mechanical tests by applying pure shear loads. The microhardness profile of the brazed joint indicated that W remained with the as-received hardness but CuCrZr base material was softened after the brazing procedure. Shear strength of 96 ± 15 MPa was obtained for the brazed joint and fracture propagated at the W-braze interface.


2015 ◽  
Vol 1128 ◽  
pp. 242-253
Author(s):  
Ioan Catalin Mon ◽  
Mircea Horia Tierean ◽  
Adel Nofal

The present research is dedicated to weldability of Austempered Ductile Iron (ADI) and Ductile Iron (DI) using Shielded Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW) methods. The welds were done using the arc welding process with Nickel base filler materials: ENi-Cl and ENiFe-Cl-A. Each weldment was examined visually, with X-rays and mechanical tests. After the mechanical tests, tensile test and impact properties of the welded joint are lower than mechanical properties of the ADI base material using ENiFe-Cl-A filler metal and GTAW process. This type of filler metal ENiFe-Cl-A can be applied successfully only for repair by welding of ADI parts. Using ENi-Cl filler metal with GTAW process applied to DI, the mechanical tests, tensile test and hardness of the welded joint are greater than mechanical properties of the DI base material. This procedure can be applied for welding. In case on DI welded using SMAW with ENi-Cl electrodes, the hardness of the welded joint is lower than the hardness of base material. This procedure can be applied only for repair by welding.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3083
Author(s):  
Alhanoof Aldegheishem ◽  
Modhi AlDeeb ◽  
Khold Al-Ahdal ◽  
Mohammad Helmi ◽  
Eman I. Alsagob

Knowledge about the influence of fillers in denture base resin is vague. This systematic review aimed to report the reinforcing effect of fillers on the mechanical properties of denture base resin by following PRISMA guidelines. Two electronic databases (Pubmed/Medline & Web of Science) were searched for articles using the keywords: fibers in denture base, fillers in denture base, and reinforcement of denture base. Laboratory studies complying with the inclusion criteria were reviewed according to the set protocol. The established focus question was: “Do reinforcing fillers positively influence the mechanical properties of polymethyl methacrylate (PMMA) heat polymerized denture base material?” A total of twenty-nine relevant papers qualified for final inclusion. Of these, 24 were determined to have a moderate risk of bias. Micron or nano-sized metal/metal oxides particles and glass fibers were the frequently used reinforcing agents. The trend of evaluating fractural strength (FS) was common. Most of the studies limited the use of reinforcing agents up to 5 wt.%. FS, fracture toughness (FT), and impact strength (IS) tend to increase if the fillers are chemically bonded and well-dispersed in denture base resin. Though fillers with a higher elastic modulus increase the hardness of the reinforced denture base resin, they compromise other mechanical properties. Well-dispersed lower filler loading PMMA denture base resin can enhance the FS, FT, and other related mechanical properties.


2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.

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.


2020 ◽  
Vol 38 (3B) ◽  
pp. 104-114
Author(s):  
Samah M. Hussein

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.


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