scholarly journals Microstructure and Mechanical Properties of the Butt Joint in High Density Polyethylene Pipe

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Pashupati Pokharel ◽  
Yoonsang Kim ◽  
Sunwoong Choi
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
High Density Polyethylene ◽  
Weld Zone ◽  
Butt Joint ◽  
High Density ◽  
Cooling Time ◽  
Tensile Fracture ◽  
Microstructure And Mechanical Properties ◽  
Dog Bone

The microstructure and mechanical properties of the butt joint in high density polyethylene (HDPE) pipes were evaluated by preparing the joints with increasing the cooling time from 10 s to 70 s before pressure created for fusion of the pipes. Here, cold fusion flaws in HDPE butt joint were created with increasing the cooling time around 70 s caused by the close molecular contact followed by insufficient interdiffusion of chain segments back and forth across the wetted interface. The tensile failure mechanism of the welded pipes at different fusion time was projected based on the tensile test of dog-bone shaped, fully notched bar type as well as round U-notched specimens. The mechanical properties of the joints at different fusion time were correlated with the corresponding fracture surface morphology. The weld seam as well as tensile fracture surfaces were etched using strong oxidizing agents. The crystallinity of surface etched weld zone by potassium permanganate based etchant was found higher than unetched sample due to the higher susceptibility of amorphous phase of polyethylene with oxidizing agent. The U-notched tensile test of butt welded HDPE pipe and surface etching of the weldments provided clear delineation about the joint quality.

Enhancing Mechanical Properties of Polyvinyl Alcohol Fiber Reinforced High Density Polyethylene Composites

2018 ◽  
Vol 777 ◽  
pp. 27-31
Author(s):  
Achmad Chafidz ◽  
Ariany Zulkania ◽  
Tintin Mutiara ◽  
Prima A. Handayani ◽  
Muhammad Rizal
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Tensile Test ◽  
High Density Polyethylene ◽  
High Density ◽  
Sem Images ◽  
Melt Compounding ◽  
Twin Screw ◽  
Pva Fiber ◽  
Surface Morphologies

In this work, high density polyethylene (HDPE)/polyvinyl alcohol (PVA) fiber composites have been fabricated via melt compounding by employing a twin-screw extruder. The resulted composites samples of four different PVA loadings (i.e. 0, 5, 10, 20 wt%) were then characterized via tensile test to investigate the effect of PVA loadings on their mechanical properties (i.e. modulus elasticity, tensile strength, toughness, and strain at break). Additionally, the surface morphologies of the composites (i.e. cryo-fractured and tensile fractured samples) were also studied by using a scanning electron microscopy (SEM). The SEM micrographs on the cryo-fractured sample showed that PVA fibers were perfectly embedded and well blended in HDPE matrix. Whereas, the SEM images of tensile-fractured samples showed that there was a fibrillation effect on the neat HDPE, while in the composites sample, there was an evident of broken fibers. Additionally, from the tensile test results, the modulus elasticity of the composites has increased by approximately 16, 39, and 81% (as compared to the neat HDPE) for PVAC-5, PVAC-10, and PVAC-20, respectively. Whereas, the toughness and strain at break of the composites have decreased.

Microstructure and Mechanical Properties of Friction Stir Welded AA2195-T0

2016 ◽  
Vol 857 ◽  
pp. 266-270 ◽  
Author(s):  
Ho Sung Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo ◽  
Kyung Ju Min
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Weld Zone ◽  
Microscopic Analysis ◽  
Butt Joint ◽  
Fusion Welding ◽  
Electron Microscopic ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties

Aluminum-copper-lithium alloy is a light weight metal that has been used as substitute for conventional aerospace aluminum alloys. With addition of Li element, it has lower density but higher strength. However these aluminum alloys are hard to weld by conventional fusion welding, since they often produce porosities and cracking in the weld zone. It is known that solid state welding like friction stir welding is appropriate for joining of this alloy. In this study, friction stir welding was performed on AA2195 sheets, in butt joint configuration in order to understand effects of process parameters on microstructure and mechanical properties in the weld zone. The results include the microstructural change after friction stir welding with electron microscopic analysis of precipitates.

scholarly journals MANUFACTURING THINNED FRICTION-STIR WELDED 1050 ALUMINUM BY POST ROLLING: MICROSTRUCTURE AND MECHANICAL PROPERTIES

2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Sina Zinatlou Ajabshir ◽  
Mohsen Kazeminezhad ◽  
Amir Hossein Kokabi
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Cold Work ◽  
Weld Zone ◽  
Travel Speed ◽  
Thin Sheets ◽  
Friction Stir ◽  
Aluminum Sheets ◽  
Microstructure And Mechanical Properties ◽  
Cold Worked

One of the friction-stir welding (FSW) limitations is joining thin sheets in sheet-metal manufacturing. To solve this limitation, thicker sheets can be welded with FSW and then rolled to a thinner thickness. This can improve the mechanical properties and save the weld zone soundly. In this work, 3-mm aluminum sheets were joined with FSW. The microstructure and mechanical properties of the samples were assessed at various rotational speeds (w) and travel speeds (v). Then, the welded samples were cold worked (CW) by rolling them at different percentages so that the samples were 2 mm and 1 mm thick. The effects of welding and post rolling on the mechanical properties and a failure analysis were deliberated. It was shown that welding reduces the transverse ultimate tensile strength (UTS) of FSWed samples by up to 29 % compared to the UTS of the base metal (BM), while rolling FSWed samples increased the UTS of the cold-worked FSWed samples by up to 94.7 % in comparison to the UTS of FSWed samples. Also, during the tensile test of the specimens FSWed at a lower travel speed, a fracture occurred at the stir zone (SZ)/thermo-mechanically affected zone (TMAZ) interface, on the advancing part; however, at a higher travel speed, it occurred at the interface of the heat-affected zone (HAZ) and TMAZ, on the retreating part. Moreover, during the tensile test of the cold-worked FSWed samples, the failure took place at the HAZ and the interface of the SZ and TMAZ, respectively. The UTS was risen by increasing the cold work. The UTS of a specimen FSWed at 50 mm/min and 1200 min–1 went up from 76 MPa to 124 MPa due to 33-% cold work and to 148 MPa due to 66-% cold work; meanwhile, the fracture occurred at the SZ/TMAZ interface or TMAZ of most of the post-rolled FSWed samples.

Effects of MAPE Modified on Physico-Mechanical Properties of Silvergrass Reinforced High Density Polyethylene Composites

2013 ◽  
Vol 423-426 ◽  
pp. 53-57
Author(s):  
Wang Wang Yu ◽  
Cai Hong Li ◽  
Juan Li ◽  
Jian Peng Zhang ◽  
Chang Wei Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Injection Molding ◽  
Differential Scanning Calorimeter ◽  
High Density Polyethylene ◽  
Nucleating Agent ◽  
High Density ◽  
Tensile Fracture ◽  
Sem Images

In this study, silvergrass (SV) reinforced high density polyethylene (HDPE) composites (WPCs) were prepared by injection molding. The effects of maleated polyethylene (MAPE), slivergrass fibers content on the mechanical, Differential scanning calorimeter, morphologies of WPCs were investigated. It was found that the mechanical properties of the SV reinforced HDPE composites can be improved by MAPE treatment. The highest tensile strength and flexural strength of the composites can be reached with 40% and 50% SV contents at the fixed 8% MAPE respectively. The SV can be the nucleating agent with the addition of MAPE. SEM images of tensile fracture surfaces of treated composites demonstrated better fiber-matrix adhesion.

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