scholarly journals Experiment on Strength and Failure Behavior of Sandstone Containing Pre-Existing Cracks Under Brazilian Compression

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Process ◽  
Experimental Results ◽  
Failure Behavior ◽  
Axial Deformation ◽  
Scanning Electron

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.

Study of Microstructure and Mechanical Properties of Extrued Spray Forming Al-8.5Fe-1.3V-1.7Si Alloy

2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Yield Strength ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
Extrusion Process ◽  
Spray Forming ◽  
Microstructure And Mechanical Properties ◽  
Scanning Electron

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%.

Effect of polyamide 6 on the mechanical behavior of thermoplastic polyurethanes/polyamide 6 blends

2021 ◽  
pp. 095440542110406
Author(s):  
Nga Thi-Hong Pham
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Behavior ◽  
Thermoplastic Polyurethane ◽  
Polyamide 6 ◽  
Thermoplastic Polyurethanes ◽  
Microscope Images ◽  
Scanning Electron

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.

The Mechanical Properties and Thermodynamic Study on Polypropylene/Talc Composites

2014 ◽  
Vol 915-916 ◽  
pp. 751-754
Author(s):  
Shao Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Impact Strength ◽  
Scanning Electron Microscope ◽  
Stearic Acid ◽  
Crystallization Rate ◽  
Scanning Calorimetry ◽  
Scanning Electron

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).

Mechanical Properties and Microstructures of Al-12Zn-2.4Mg-1.2Cu Alloy Extruded Sheet

2014 ◽  
Vol 893 ◽  
pp. 402-405
Author(s):  
Gang Chen ◽  
Zhi Min Zhang ◽  
Wei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Yield Strength ◽  
Scanning Electron Microscope ◽  
Optical Microscopy ◽  
Tensile Tests ◽  
Extrusion Temperature ◽  
Two Stage ◽  
Scanning Electron

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.

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
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Test ◽  
Natural Fibers ◽  
Resin Infusion ◽  
Green Material ◽  
Plastic Composite ◽  
Scanning Electron

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

scholarly journals Effect of Microstructure on Mechanical Properties of BA1055 Bronze Castings

2014 ◽  
Vol 14 (2) ◽  
pp. 73-78 ◽  
Author(s):  
J. Łabanowski ◽  
T. Olkowski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Chemical Composition ◽  
Scanning Electron Microscope ◽  
Aluminum Bronze ◽  
Marine Propellers ◽  
Casting Technology ◽  
Alloy Microstructure ◽  
Scanning Electron

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.

Microstructure and Porous Defects of a Spray-Formed and Hot Worked 7000 Aluminum Alloy

2016 ◽  
Vol 879 ◽  
pp. 1778-1782
Author(s):  
Shu Hui Huang ◽  
Zhi Hui Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Xi Wu Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hot Isostatic Pressing ◽  
Aging Treatment ◽  
Hot Extrusion ◽  
Evolution Of Microstructure ◽  
Scanning Electron

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.

Effect of Clamshells Filler Loading on the Tensile Properties of Polyhydroxybutyrate

2015 ◽  
Vol 1115 ◽  
pp. 262-265 ◽  
Author(s):  
Maizatulnisa Othman ◽  
Mohd Yusoff Hashim ◽  
Ibrahim Nor Azowa ◽  
Khalisanni Khalid ◽  
Souad A. Mohamad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Calcium Carbonate ◽  
Scanning Electron Microscope ◽  
Calcium Oxide ◽  
Filler Loading ◽  
Inorganic Filler ◽  
Biomass Resources ◽  
Scanning Electron

In this study, the abundant availability of clamshell, as the potential of the biomass resources for the production of the inorganic filler such as calcium carbonate (CaCO3) and calcium oxide (CaO) is fully utilized. In addition, the effect of filler loadings toward mechanical properties of polyhydroxybutyrate (PHB) biopolymer was studied using various ranges of loadings such as 10, 20, 30, 40 and 50 wt%. The tensile strength and modulus of PHB showed significant improvement with the incorporation of the filler up to 30 wt %, and this finding was supported by micrographs obtained from scanning electron microscope (SEM) which revealed uniform distribution of the filler in the polyhydroxybutyrate region. However, the elongations at break of the specimen shows vice versa, they start to deteriorate with the addition of the filler.

Effect of the Neodymium Content on Mechanical Properties of the Electro-Brush Plated Nano-Al2O3/Ni Composite Coating

2012 ◽  
Vol 525-526 ◽  
pp. 277-280
Author(s):  
Guo Jin ◽  
Xiu Fang Cui ◽  
Er Bao Liu ◽  
Qing Fen Li
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Composite Coating ◽  
Nanoindentation Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Cracks ◽  
Scanning Electron

The effect of the neodymium content on mechanical properties of the electro-brush plated nanoAl2O3/Ni composite coating was investigated in this paper. The microstructure and phase structure were studied with scanning electron microscope (SEM) and X-ray diffraction (XRD). The hardness and abrasion properties of several coatings with different neodymium content were studied by nanoindentation test and friction / wear experiment. Results show that the coatings are much finer and more compact when the neodymium was added, and the hardness and abrasion property of the coatings with neodymium were improved obviously. Besides, the small cracks conduced by the upgrowth stress in the coatings were ameliorated when the rare earth neodymium was added. The improvement mechanism was further discussed.

Effect of Functionalized MWCNT on the Mechanical and Dielectric Properties of PMMA Nanocomposites

2018 ◽  
Vol 18 (06) ◽  
pp. 1850035
Author(s):  
Punyapriya Mishra ◽  
Narasingh Deep ◽  
Sagarika Pradhan ◽  
Vikram G. Kamble
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Dielectric Properties ◽  
Conductive Polymer ◽  
Mechanical Tests ◽  
Surface Structures ◽  
Scanning Electron

Carbon nanotubes (CNTs) are widely explained in fundamental blocks of nanotechnology. These CNTs exhibit much greater tensile strength than steel, even almost similar to copper, but they have higher ability to carry much higher currents, they seem to be a magical material with all these mentioned properties. In this paper, an attempt has been made to incorporate this wonder material, CNT, (with varying percentages) in polymeric matrix (Poly methyl methacrylate (PMMA)) to create a new conductive polymer composite. Various mechanical tests were carried out to evaluate its mechanical properties. The dielectric properties such as dielectric loss and dielectric constant were evaluated with the reference of temperature and frequency. The surface structures were analyzed by Scanning Electron Microscope (SEM).

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