scholarly journals Aplikasi teknik manufaktur vacuum assested resin infusion (vari) untuk peningkatan sifat mekanik komposit plastik berpenguat serat abaca (AFRP)

2018 ◽  
Vol 16 (1) ◽  
pp. 19
Author(s):  
Abubakar Dabet ◽  
Indra Indra ◽  
Teuku Hafli

AbstrakInovasi dalam bidang material komposit menuntut terciptanya material yang lebih ramah lingkungan.  Saat ini komposit serat alam (green material) patut dipertimbangkan menjadi material yang sangat berpotensi untuk mensubstitusi komposit serat sintetis sebagai material teknik. Serat alam mempunyai kekurangan karena mempunyai scatter sifat mekanik yang sangat besar. Salah satu cara untuk mengatasi kekurangan tersebut adalah melalui pemilihan proses manufaktur (fabrikasi) komposit. Tujuan penelitian ini adalah membuat prototype komposit plastik berpenguat serat abaca (AFRP)  menggunakan metode Vakum (Vacum Assested Resin Infusion (VARI)). Semua spesimen dilakukan postcure pada suhu 800 C selama 2 jam. Sifat mekanik dari komposit dievaluasi uji tariknya. Komposit AFRP difabrikasi dengan fraksi volume (Vf) : 20%, 30% , 40%, serta ukuran spesimen uji (140x5x1) mm. Dengan proses fabrikasi sebagai berikut: 1) Serat abaca disusun dalam cetakan kaca yang memanjang sejajar (00) kemudian dimasukkan ke dalam kantong plastik vakum. 2) Resin dicampur hardener dialirkan kedalam cetakan yang sudah kondisi vakum. Metode cetakan ini dapat menghilangkan gelembung udara di dalam komposit sehingga diharapkan kekuatan tarik komposit menjadi lebih tinggi.  Bahan-bahan yang diperlukan dalam penelitian ini adalah: Serat abaca, Resin BTQN 157-EX, Hardener MEKPO dan Wax. Peralatan yang diperlukan adalah: Instalasi cetak vakum, Alat uji tarik, Kamera digital, dan Scanning Electron Microscope (SEM). Penampang patahan diselidiki untuk mengidentifikasi mekanisme perpatahannya.  Hasil penelitian menunjukkan bahwa kekuatan dan regangan tarik komposit memiliki harga optimum untuk (Vf) 40%, yaitu 257 Mpa dan 0.44%.  Penampang patahan komposit diklasifikasikan sebagai jenis patah slitting in multiple area sehingga dapat disimpulkan bahwa komposit plastik berpenguat serat abaca memiliki potensi yang cukup besar untuk diaplikasikan sebagai material struktural. Kata kunci: Serat Abaca, AFRP, Kekuatan tarik, VARI, Scanning Electron Microscope AbstractInnovation in composite materials demands the creation of more environmentally friendly materials. Currently the composite of natural fibers (green material) should be considered to be a material that has the potential to substitute synthetic fiber composites as engineering materials. Natural fibers have disadvantages because they have a very large mechanical properties scatter. One way to overcome these shortcomings is through the selection of a composite manufacturing (fabrication) process. The purpose of this research is to make prototype of plastic composite with abaca fiber (AFRP) using Vacuum Assured Resin Infusion (VARI)). All specimens were performed postcure at 800 C for 2 hours. The mechanical properties of the composites are evaluated by the tensile test. The AFRP composite is fabricated by volume fraction (Vf): 20%, 30%, 40%, as well as test specimen size (140x5x1) mm. With the fabrication process as follows: 1) Abaca fiber is arranged in a parallel laminated glass mold (00) then put in a vacuum plastic bag. 2) The resin in the mixed hardener flowed into a mold that has a vacuum condition. This mold method can remove air bubbles inside the composite so that the expected composite tensile strength becomes higher. The materials needed in this research are: Abaca fiber, BTQN 157-EX Resin, MEKPO and Wax Hardener. The necessary equipment are: Vacuum printing installation, Tensile test equipment, Digital camera, and Scanning Electron Microscope (SEM). Fault cross sections were investigated to identify the fracture mechanism. The results showed that the strength and composite tensile strain had the optimum price for (Vf) 40%, ie 257 Mpa and 0.44%. The composite fault cross section is classified as a type of broken slitting in multiple areas so it can be concluded that the plastic composite of abaca fibers has considerable potential to be applied as a structural material. Keywords: Abaca Fiber, AFRP, Tensile Strength, VARI, Scanning Electron Microscope

2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu

In this paper, the Al-8.5Fe-1.3V-1.7Si alloys were fabricated by spray forming and extrusion process. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that the tensile strength of the extrued alloys can reach 353MPa, the yield strength 300MPa, elongation 19.12%, at room temperature. At 250°C, the tensile strength of the extrued alloys can reach 221MPa, the yield strength 208MPa, elongation 13.33%.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.


Author(s):  
Nga Thi-Hong Pham

Ductility and tensile strength are among the basic mechanical properties of polymers. Generally, it is difficult to enhance the ductility without significantly reducing the tensile strength. In this study, thermoplastic polyurethane (TPU) is mixed with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% polyamide 6 (PA6). The results show that the sample containing 100% TPU has the largest elongation of 690.5%. When PA6 is added, the elongation decreases gradually to 635.0%, 623.1%, 529.5%, 476.0%, 391.3%, and 242.8%, corresponding to 2.5%, 5%, 7.5%, 10%, 12.5%, and 100% PA6, respectively. The tensile strengths are 36.7, 33.8, 29.4, 26.5, 23.1, and 24.9 MPa, corresponding to 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PA6 samples, respectively. The tensile strength decreases gradually when the PA6 content is increased. Notably, the tensile strength of the 12.5% PA6 sample increases compared to the 10% PA6 sample. In addition, the hardness of the TPU/PA blend increases slightly as the PA6 ratio is increased. Finally, scanning electron microscope images demonstrate that PA6 particles act as particles dispersed or dissolved in TPU/PA blends.


2013 ◽  
Vol 711 ◽  
pp. 95-98
Author(s):  
Xiao Liu ◽  
Jing Long Liang

The effect of Ce on structure and mechanical properties of 21Cr11Ni austenitic stainless steels were studied by metallographic examination, scanning electron microscope (SEM), tensile test. The results show that the proper amount of Ce can refine microstructure of austenitic stainless steel. Fracture is changed from cleavage to ductile fracture by adding Ce to austenitic stainless steel. 21Cr11Ni stainless steel containing 0.05% Ce can improve its high temerature strength, and the strength is increased 21.81% at 1073K respectively comparing with that of 21Cr11Ni stainless steel without Ce.


2014 ◽  
Vol 915-916 ◽  
pp. 751-754
Author(s):  
Shao Hui Wang

The composites of PP/Talc modified by stearic acid were prepared and its effect on the properties of PP/Talc composites was investigated in this paper. The tensile strength and impact strength of PP/Talc composites increased about 15% and 30% compared with pure PP respectively. Based on surface analysis by scanning electron microscope (SEM), the Talcparticles buried well in PP matrix when the Talc was coated with the stearic acid. At the same time, it was found that Talc significantly increased the crystallization temperature and crystallization rate of PP by differential scanning calorimetry (DSC).


2014 ◽  
Vol 893 ◽  
pp. 402-405
Author(s):  
Gang Chen ◽  
Zhi Min Zhang ◽  
Wei Chen

Mechanical properties of Al-12Zn-2.4Mg-1.2Cu alloy extruded sheet were investigated by tensile tests. Microstructures were investigated by optical microscopy (OM) and scanning electron microscope (SEM). The result shows that no matter in the L direction or in the T direction, the tensile strength and yield strength decrease with the increasing of the extrusion temperature in different states. The tensile strength and yield strength in the L direction are higher than in the T direction at different extrusion temperatures and different treatment states. When temperature is 340°C, the highest tensile strength is 780 MPa and the highest yield strength is 753 MPa in the two-stage solution and two-stage aging state. The reason for the higher mechanical properties are in the L direction in different states is mainly depend on the distribution direction of the grains.


Author(s):  
Unueroh Ufuoma Georgina ◽  
Basil Onyekpe

Corrosion is a major problem all over the world. A lot of researches on corrosion are ongoing all over the world and will continue to go on. This paper investigates the effect of corrosion on the tensile properties of AISI 1040 steel in seawater. The samples were austenised at 8300C, 9300C, and 10300C, while some were not. The austenised samples were quenched in water and tempered at 5000C. The samples were further machined into tensile test specimens and then exposed to stagnant aerated seawater. Two samples each from each austenised temperature were tested using a tensile test machine at every 15-days interval, for a duration of 90 days. Some of the fracture surfaces were examined using scanning electron microscope. The results shows a 25% decrease in tensile strength for as received sample, 20.1% decrease for samples austenised at 8300C, 20.9% decrease for samples austenised at 9300C and 22.4% decrease for samples austenised at 10300C at the end of the 90thday.


2014 ◽  
Vol 14 (2) ◽  
pp. 73-78 ◽  
Author(s):  
J. Łabanowski ◽  
T. Olkowski

Abstract The article presents research results performed on aluminum bronze CuAl10Fe5Ni5 (BA1055) castings used for marine propellers. Metallographic studies were made on light microscope and a scanning electron microscope to assess quantitatively and qualitatively the alloy microstructure. It has been shown that the shape, size and distribution of the iron-rich к−phase precipitates in bronze microstructure significantly affect its mechanical properties. With an increase in the number of small к−phase precipitates increases the tensile strength of castings, while the presence of large globular precipitates improves ductility. Fragmentation and shape of κ−phase precipitates depends on many factors, particularly on the chemical composition of the alloy, Fe/Ni ratio, cooling rate and casting technology.


2016 ◽  
Vol 879 ◽  
pp. 1778-1782
Author(s):  
Shu Hui Huang ◽  
Zhi Hui Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Xi Wu Li ◽  
...  

The evolution of microstructure and porous defects of a spray-formed 7000 Aluminum alloy is researched in this paper. The spray-formed alloy is treated by hot isostatic pressing (HIP), homogenization, hot extrusion, solution and aging treatment. Metallographic microscope, scanning electron microscope (SEM) and tensile test are used to research the microstructure and mechanical properties. The results show that, there are two kinds of porous defects in spray-formed alloy, which has gas and no gas. The porous defects of spray-formed ingot can be mostly eliminated by HIP and hot extrusion. After solution and aging treatment, the tensile strength and elongation reach 757MPa and 10.2%, respectively.


2010 ◽  
Vol 146-147 ◽  
pp. 1415-1418
Author(s):  
Ronɡ Hua Zhang ◽  
Yon Gan Zhang ◽  
Bao Hong Zhu

In this paper, the Al-8.5Fe-1.3V-1.7Si alloy was fabricated by spray forming and forging processes. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that spray formed Al-8.5Fe-1.3V-1.7Si alloy after pressing plus can forging processes displays excellent microstructure and characterization.


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