Influence of Fabricated Process on Mechanical Properties of Porous SiC-Particle/Si3N4 Composites

2007 ◽  
Vol 336-338 ◽  
pp. 1320-1323 ◽  
Author(s):  
Hong Jie Wang ◽  
Wen Zhang ◽  
Yu Bai ◽  
Guan Jun Qiao ◽  
Ji Qiang Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Powder Compact ◽  
High Strength ◽  
Uniform Structure ◽  
High Porosity ◽  
Gel Casting ◽  
N2 Atmosphere ◽  
Porous Sic ◽  
Sic Particle

In this paper, the mechanical properties of porous Si3N4/SiC composite prepared by different forming method (uniaxial pressing and gel-casting) were compared. Using gelcasting and two steps sintering technology, the porous SiC-particle/Si3N4 composites with a high strength, uniform structure and a relative high porosity were obtained by adding a little amount of nano carbon in slurry. The flexural strength of optimized material reaches to 100MPa and its porosity is more than 60%. But using uniaxial pressing and sintering at N2 atmosphere, because the green bodies have the high density, and the density distribution of a powder compact was not uniform, the flexural strength is not high, and at the same time, the microstructure is not uniform also.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

scholarly journals Experimental Investigation on Mechanical Properties of Hybrid Steel and Polyethylene Fiber-Reinforced No-Slump High-Strength Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tian-Feng Yuan ◽  
Jin-Young Lee ◽  
Kyung-Hwan Min ◽  
Young-Soo Yoon
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Flexural Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced ◽  
Flexural Toughness ◽  
Strength Concrete ◽  
Polyethylene Fiber ◽  
Energy Dissipation Capacity

This paper presents experimental investigations on the mechanical properties of no-slump high-strength concrete (NSHSC), such as the compressive and flexural strength. First, to determine the proper NSHSC mixtures, the compressive and flexural strength of three different water-to-binder ratios (w/b) of specimens with and without polyethylene (PE) fiber was tested at test ages. Then, the effect of hybrid combinations of PE fiber and steel fiber (SF) on the compressive strength, flexural strength, flexural toughness, and flexural energy dissipation capacity was experimentally investigated. Furthermore, the various hybrid fiber-reinforced NSHSCs were evaluated, and their synergy was calculated, after deriving the benefits from each of the individual fibers to exhibit a synergetic response. The test results indicate that a w/b of 16.8% with or without fibers had lower strength and flexural strength (toughness) than those of other mixtures (w/b of 16.4% and 17.2%). Specimens with a hybrid of SF and short PE fibers exhibited a higher compressive and flexural strength, flexural toughness, energy dissipation capacity, and fiber synergy in all considered instances.

Preparation of In Situ Synthesized SiC Particles Reinforced Highly Porous Si3N4 Ceramics by Gel-Casting

2008 ◽  
Vol 368-372 ◽  
pp. 898-900
Author(s):  
Hong Zeng ◽  
Hong Jie Wang ◽  
Juan Li Yu ◽  
Dan Bo Lin ◽  
Guan Jun Qiao ◽  
...  
Keyword(s):  
High Strength ◽  
Xrd Analysis ◽  
High Porosity ◽  
Water Displacement ◽  
Contributing Factors ◽  
Homogeneous Microstructure ◽  
Three Point Bending ◽  
Gel Casting ◽  
Sic Particles ◽  
Highly Porous

In this paper, highly porous Si3N4 ceramics with high strength, homogeneous microstructure were fabricated by introducing a proper amount of nanometer carbon in the Si3N4 slurry by gel-casting. Scanning electron microscopy, X-ray diffraction, Archimedes water-displacement method and three-point bending tests were employed to analyze the microstructures and mechanical properties of the sintered bodies. It was shown by the XRD analysis that SiC particles were formed in the sintered bodies. The pillar β- Si3N4 morphology, homogeneous microstructure and the SiC particles as a reinforcement phase are the contributing factors for high porosity and good mechanical behavior.

High Strength and Toughness Al2O3 Composite Materials for the Improvement of Ceramic Channel in SRL Hot Dipping System

2010 ◽  
Vol 658 ◽  
pp. 416-419 ◽  
Author(s):  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Bhupendra Joshi ◽  
Sung Hun Cho ◽  
Soo Wohn Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Composite Materials ◽  
Flexural Strength ◽  
Fracture Strength ◽  
Hot Pressing ◽  
High Strength ◽  
Economic Feasibility ◽  
Different Content ◽  
Strength And Toughness

The ceramic channel is very important in SRL hot dipping system. High strength and fracture toughness of ceramic channel materials can improve the quality, productivity and economic feasibility of zinc plated steel. The purpose of this research was to find out the most suitable conditions of the ceramic channel that have best fracture strength and fracture toughness. The hot pressed composite materials was carried out by hot pressing Al2O3 with different content of ZrO2. The composite contained from 0-20 wt.% ZrO2. Hot pressed composite materials were observed for mechanical properties (density, hardness, fracture toughness and flexural strength) and microstructure.

scholarly journals Mechanical properties and microstructure of recycled mortar reinforced with hybrid fiber

2018 ◽  
Vol 7 (4) ◽  
pp. 2178 ◽  
Author(s):  
Sallehan Ismail ◽  
Mohammad Asri Abd Hamid ◽  
Zaiton Yaacob ◽  
Dzulkarnaen Ismail ◽  
Hazizan Md Akil
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Mechanical Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
High Strength ◽  
Strength Properties ◽  
Recycled Aggregate ◽  
Hybrid Fiber ◽  
Hybrid Fibers

This study investigated the hybrid effects of two types of microfiber, namely, polypropylene and nylon, on the mechanical properties of high-strength mortar, which produced fine recycled aggregate (FRA). The amount of microfibers was maintained at a volumetric fraction of 0.6%. The microstructure and mechanical strength properties (compressive strength and flexural strength) of recycled mortar reinforced with hybrid-size microfibers were evaluated at various curing ages. Experimental results show that the inclusion of hybrid fibers significantly influenced the mechanical performance of the recycled mortar. The hybridization fiber at volume fraction 0.3% polypropylene + 0.3% nylon yielded the most promising mechanical performance. Enhancements of 8% on compressive and 11% flexural strength were achieved at 28 days. Scanning electron microscopy observations revealed that reinforcement at the microscale prohibited the initiation and growth of cracks at the micro level. High loads were required to form macrocracks within composites, thereby improving the mechanical strength of the mortar matrix.  

Effect of Processing Condition on the Microstructure and Mechanical Properties of Ti3SiC2/SiC Composites

2010 ◽  
Vol 658 ◽  
pp. 352-355 ◽  
Author(s):  
Hong Feng Yin ◽  
Lin Lin Lu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Processing Condition ◽  
High Porosity ◽  
Pressing Temperature ◽  
Pressing Method ◽  
Microstructure And Mechanical Properties ◽  
Sic Composites

Ti3SiC2/SiC composites were fabricated by reactive hot pressing method. Effect of processing condition on the microstructure and mechanical properties of the composites were investigated. The results showed that: (1) Hot-pressing temperature influenced the phase constituent of Ti3SiC2/SiC composites. The flexural strength and fracture toughness of composites increased with hot pressing temperature. (2) The flexural strength and fracture toughness of composites increased when the content of SiC was increased. When the SiC content was 30wt% the flexural strength and fracture toughness of Ti3SiC2/SiC composite were 371MPa and 6.9MPa•m1/2 respectively. However, when the content of SiC reached 50wt%, the flexural strength and fracture toughness of composites decreased due to high porosity in the composites. (3) The flexural strength and fracture toughness of composites increased with the particle size of SiC added in composites. (4) Ti3SiC2/SiC composites were non-brittle at room temperature.

Mechanical Properties of Modified Polypropylene Coarse Fiber-Reinforced, High-Strength, Lightweight Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1499-1506
Author(s):  
Rong Hui Zhang ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
High Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume

In this study, the effect of micro-expansion high strength grouting material (EGM) and Modified polypropylene coarse fiber (M-PP fiber) on the mechanical properties of lightweight concrete are investigated. The influence of EGM and M-PP fiber on compressive strength , flexural strength and drying shrinkage of concrete are researched, and flexural fracture toughness are calculated. Test results show that the effect of EGM and M-PP fiber volume fraction (Vf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly enhanced, and the rate of shrinkage is obviously decreased. It is observed that the shape of the descending branch of load-deflection and the ascending branch of shrinkage-age tends towards gently with the increase of Vf. And M-PP fiber reinforced lightweight aggregate concrete is more economical.

Low-Temperature Sintering of Porous Silicon Carbide Ceramics with H3PO4 as an Additive

2018 ◽  
Vol 281 ◽  
pp. 311-315 ◽  
Author(s):  
Tian Gu ◽  
Fei Chen ◽  
Hai Long Yuan ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Phosphoric Acid ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Strength ◽  
High Porosity ◽  
Low Temperature Sintering ◽  
Sic Ceramic ◽  
Carbide Ceramics ◽  
Porous Sic ◽  
Silicon Carbide Ceramics

In this paper, the raw SiC powder is oxidized at high temperature (1000 °C for 4h), and a layer of SiO2oxide film is formed on the surface of SiC particles. By adding phosphoric acid, phosphoric acid reacts with SiO2at lower temperatures to form phosphate. Phosphate decomposition produces gas to create pores. At 1200 °C, the phosphate is completely decomposed into SiO2, and a large amount of gas is produced to prepare porous SiC ceramic with high porosity and high strength. The effects of H3PO4content on the phase composition, microstructure, porosity and mechanical properties of the prepared porous SiC ceramic were investigated. With the increase of H3PO4content, the porosity increased and the bending strength decreased. The results suggest that at the sintering temperature of 1200 °C, the porosity of the samples can reach 58.3%~71.2%, while the bending strength of them can reach 8.72~31.09 MPa.

scholarly journals Underwater Local Cavity Welding of S460N Steel

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5535
Author(s):  
Jacek Tomków ◽  
Anna Janeczek ◽  
Grzegorz Rogalski ◽  
Adrian Wolski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Standard Deviation ◽  
Welded Joints ◽  
Welded Joint ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Carbon Equivalent ◽  
High Porosity ◽  
Weld Porosity

In this paper, a comparison of the mechanical properties of high-strength low-alloy S460N steel welded joints is presented. The welded joints were made by the gas metal arc welding (GMAW) process in the air environment and water, by the local cavity welding method. Welded joints were tested following the EN ISO 15614-1:2017 standard. After welding, the non-destructive—visual, penetrant, radiographic, and ultrasonic (phased array) tests were performed. In the next step, the destructive tests, as static tensile-, bending-, impact- metallographic (macroscopic and microscopic) tests, and Vickers HV10 measurements were made. The influence of weld porosity on the mechanical properties of the tested joints was also assessed. The performed tests showed that the tensile strength of the joints manufactured in water (567 MPa) could be similar to the air welded joint (570 MPa). The standard deviations from the measurements were—47 MPa in water and 33 MPa in the air. However, it was also stated that in the case of a complex state of stress, for example, bending, torsional and tensile stresses, the welding imperfections (e.g., pores) significantly decrease the properties of the welded joint. In areas characterized by porosity the tensile strength decreased to 503 MPa. Significant differences were observed for bending tests. During the bending of the underwater welded joint, a smaller bending angle broke the specimen than was the case during the air welded joint bending. Also, the toughness and hardness of joints obtained in both environments were different. The minimum toughness for specimens welded in water was 49 J (in the area characterized by high porosity) and in the air it was 125 J (with a standard deviation of 23 J). The hardness in the heat-affected zone (HAZ) for the underwater joint in the non-tempered area was above 400 HV10 (with a standard deviation of 37 HV10) and for the air joint below 300 HV10 (with a standard deviation of 17 HV10). The performed investigations showed the behavior of S460N steel, which is characterized by a high value of carbon equivalent (CeIIW) 0.464%, during local cavity welding.

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