In Situ Synthesis and Mechanical Properties of TiN-Si2N2O-Si3N4 Composites

2008 ◽  
Vol 403 ◽  
pp. 227-230
Author(s):  
Hajime Kiyono ◽  
Shiro Shimada
Keyword(s):  
Bending Test ◽  
Vickers Indentation ◽  
Composite Ceramics ◽  
Indentation Method ◽  
Amorphous Sio2 ◽  
Mixed Powder ◽  
Sintered Composite ◽  
Four Point Bending ◽  
Four Point Bending Test

Si3N4-Si2N2O-TiN composite ceramics were in-situ fabricated by using following reactions of (1) 3TiO2 + Si3N4 → 3TiN + 3SiO2 + N2 and (2) Si3N4+ SiO2 → 2Si2N2O. The mixed powder of α-Si3N4, Al2O3, Y2O3 and TiO2 was hot-pressed at 24 MPa and 1800°-1900°C for 1-4 h in N2. Sintered composite ceramics were characterized by XRD, SEM, TEM, four-point bending test and Vickers indentation method. XRD results and TEM observation showed that TiN and amorphous SiO2 were formed at 1250°C by the reaction (1), and the Si2N2O phase formed by reaction (2) above 1800°C. Si3N4-Si2N2O-TiN composites consisted of ≥2 m sized Si2N2O grains with TiN and Si3N4 grains. Hardness and fracture strength of the composites were comparable to those of Si2N2O ceramics, with fracture toughness being improved at 5vol% TiN containing composites.

scholarly journals Effect of marine environment on the behaviour of concrete structures reinforced by composite materials

2020 ◽  
Vol 21 (4) ◽  
pp. 407
Author(s):  
Chafika Djelal ◽  
Mardy Long ◽  
Abdelkader Haddi ◽  
Julien Szulc
Keyword(s):  
Marine Environment ◽  
Concrete Structures ◽  
Bending Test ◽  
Experimental Investigations ◽  
The North ◽  
Four Point Bending ◽  
Failure Loads ◽  
Four Point Bending Test ◽  
Living Organisms

This study deals with experimental investigations of beam performances in a marine environment. Two kinds of concrete beams, unreinforced and reinforced with carbon plates and carbon rods, are being tested. The first one is stored in a laboratory, the other is exposed to a marine environment located in the north of France. After 12 months, all beams are tested via a four-point bending test in a laboratory. Results obtained have shown that beams stored in marine environment have a better behaviour than those stored in laboratory. It should be noted that no damage has occurred on these beams. However, we observe a significant increase of load of about 32% to 48% causing the first crack observed on the beams stored in marine environment compared to those stored in the laboratory. This means that beams in situ offer increased stiffness and a slight gain of failure loads. This may be due to the development of living organisms (in a marine environment) which acted as additional adhesive and sealing, providing a protection of concrete structures against damage.

scholarly journals Structural behaviour of PSCC slab panel under four-point bending test

2021 ◽  
Vol 1144 (1) ◽  
pp. 012039
Author(s):  
M A Iman ◽  
N Mohamad ◽  
A A A Samad ◽  
Steafenie George ◽  
M A Tambichik ◽  
...  
Keyword(s):  
Bending Test ◽  
Structural Behaviour ◽  
Four Point Bending ◽  
Four Point Bending Test

Manufacturing a carbon/epoxy NACA 23018 airfoil skin using a circular braiding machine: experimental and numerical study

2021 ◽  
pp. 152808372199377
Author(s):  
Jalil Hajrasouliha ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Numerical Study ◽  
Filament Winding ◽  
Bending Test ◽  
Elastic Response ◽  
Manufacturing Processes ◽  
Fiber Reinforced Composite ◽  
Four Point Bending ◽  
Reinforced Composite ◽  
Four Point Bending Test ◽  
Meso Scale

In the interest of reducing the weight and also cost of blade skins, various automatic preform manufacturing processes were developed including tape laying, filament winding and braiding. Among them, the circular braiding process was found to be an efficient method in producing seamless preforms on mandrels with various geometries. In this regard, an attempt was made to produce a carbon fiber reinforced composite with the shape of NACA 23018 airfoil using a circular braiding machine. Thus, suitable wooden mandrels were manufactured using NACA 23018 airfoil coordinates, which were obtained by assuming the perimeter of 20 cm. Furthermore, both biaxially and triaxially braided preforms were produced and subsequently impregnated with epoxy resin through an appropriate fabrication method. To assess their performance, four-point bending test was carried out on samples. Ultimately, the elastic response of braided composite airfoils was predicted using a meso-scale finite element modeling and was validated with experimental results.

Research on Damage and Bending Properties of AZ31 Magnesium Alloy

2012 ◽  
Vol 184-185 ◽  
pp. 1163-1166
Author(s):  
Xi An Xie ◽  
Gao Feng Quan
Keyword(s):  
Magnesium Alloy ◽  
Applied Load ◽  
Bending Strength ◽  
Az31 Magnesium Alloy ◽  
Bending Test ◽  
Bending Properties ◽  
Four Point Bending ◽  
Heat Treated ◽  
Four Point Bending Test ◽  
Initial Cracks

Through the four-point bending test of lath-shaped heat treated AZ31 magnesium alloy, the bending properties and damage characteristics were explored. The results show that the optimal bending strength of the magnesium alloy were 355.1MPa and 259.2MPa for extruded and cast samples, respectively, after corresponding heat treatment with 350°C, 90min and 400°C, 30min. The initial cracks both occurred at the loading point after applied load exceeded the yield limit of AZ31 magnesium alloy. Surface bump, cracks and other damage morphology accompanied by a large number of twinning organizations were found on the surface of the samples.

scholarly journals Geometry Effects in Four-Point Bending Test for Thin Sheet Studied by Finite Element Simulation

2016 ◽  
Vol 57 (3) ◽  
pp. 335-343 ◽  
Author(s):  
Xiaolong Dong ◽  
Hongwei Zhao ◽  
Lin Zhang ◽  
Hongbing Cheng ◽  
Jing Gao
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Thin Sheet ◽  
Bending Test ◽  
Four Point Bending ◽  
Element Simulation ◽  
Four Point Bending Test ◽  
Geometry Effects

scholarly journals Fatigue Crack Extension in Four-point Bending Test for Steels Imitated Heat Affected Zone

2015 ◽  
Vol 64 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Hidetoshi KOBAYASHI ◽  
Noboru KONDA ◽  
Joy-A-Ka SUTEP ◽  
Ketaro HORIKAWA ◽  
Takeshi YAMAUCHI
Keyword(s):  
Fatigue Crack ◽  
Heat Affected Zone ◽  
Crack Extension ◽  
Bending Test ◽  
Four Point Bending ◽  
Four Point Bending Test
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