Effect of stitch and biaxial yarn types on the impact properties of biaxial weft knitted textile composites

2013 ◽  
Vol 20 (3) ◽  
pp. 255-264 ◽  
Author(s):  
Ozgur Demircan ◽  
Tatsuya Kosui ◽  
Shinsuke Ashibe ◽  
Yohji Hamada ◽  
Asami Nakai
Keyword(s):  
Microstructural Characterization ◽  
Optical Microscope ◽  
Textile Composites ◽  
Composite Panel ◽  
Weft Yarn ◽  
Plate Bending ◽  
Impact Properties ◽  
Three Point Bending ◽  
The Impact

AbstractWithin the scope of experiments, the effects of stitch yarn type, such as aramid, glass, and nylon, and biaxial, warp, and weft yarn type, such as aramid and glass, on biaxial weft knitted (BWK) composites were investigated. Five different types of composite panel, which include fiber contents, such as glass-glass-glass, glass-glass-nylon, glass-glass-aramid, aramid-glass-aramid, and aramid-aramid-aramid, were fabricated by hand lay-up method. After the production of composite panels, three-point bending impact and plate bending impact tests were conducted on the specimens. Microstructural characterization of the impact-tested materials was performed using an optical microscope. This study shows that composites with BWK preforms consisting of fiber combinations such as glass-glass-aramid had higher plate bending impact and three-point bending impact properties than the other four types of composite structure.

scholarly journals Microstructural Characterization of Antimony Modified Carbidic Austempered Ductile Iron

2019 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Abel. A. Barnabas ◽  
Akinlabi Oyetunji ◽  
S. O. Seidu
Keyword(s):  
Ductile Iron ◽  
Microstructural Characterization ◽  
Sem Analysis ◽  
Austempered Ductile Iron ◽  
Carbide Formation ◽  
Primary Carbide ◽  
Chunky Graphite ◽  
High Level ◽  
The Impact

In this research, Scanning Electron Microscope (SEM) analysis was conducted on the produced antimony modified carbidic austempered ductile iron for agricultural implement production. Six different alloys of carbidic austempered ductile iron with varying micro quantities of antimony elements were produced. The produced alloys were heated to austenitic temperature of 910oC, held at this temperature for 1 hour, finally subjected to austempering temperatures of 300°C and 325°C for periods of 1-3 hours. The SEM in conjunction with XRD and EDS was used for the analysis. Microstructural phase morphology, phase constituents and phase compositions were viewed with SEM, XRD and EDS respectively. The results show that various phases such as spiky graphite, blocky carbides, granular carbide, pearlite and ausferrite matrix. The XRD pattern revealed some compounds such as (Fe, Cr)3C, (primary carbide), Cr6C23 (few secondary carbide), (NiFe2O4), chromite (FeCr2O4), Cr7C3 (few eutectic carbide) and Cr3Ni2. In conclusion, it was observed in terms of morphology that chunky graphite, blocky carbide and pearlite phases were present in the cast carbidic ductile iron (CDI) without antimony addition. The CDI with varying quantities of antimony additions shows spiky graphite, granular carbides and pearlite matrix. After the samples were subjected to austempering processes, all the phases were found to be intact except the pearlite phase that transformed to ausferrite phase. The antimony element in the alloys was seen to promote the formation of pearlite phase intensively. The hardness of the samples increases as the antimony addition increases from 0.096wt.% to 0.288wt.% owing to the increase in pearlite phase, while the impact toughness reaches relatively high level, when 0.288wt.% antimony was added, probably due to the refinement of graphite nodules. All the results obtained showed that appropriate content of antimony addition plays an important role in increasing the nucleation rate of graphite nodules, and also lead to improvement in carbide formation thereby providing good balance between wear and impact properties.

scholarly journals Microstructural Characterization Of Laser Heat Treated AISI 4140 Steel With Improved Fatigue Behavior

2015 ◽  
Vol 60 (2) ◽  
pp. 1331-1334 ◽  
Author(s):  
M.C. Oh ◽  
H. Yeom ◽  
Y. Jeon ◽  
B. Ahn
Keyword(s):  
Fatigue Strength ◽  
Alloy Steel ◽  
Microstructural Evolution ◽  
Fatigue Behavior ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Heat Treated ◽  
Aisi 4140 ◽  
Ultrasonic Fatigue

Abstract The influence of surface heat treatment using laser radiation on the fatigue strength and corresponding microstructural evolution of AISI 4140 alloy steel was investigated in this research. The AISI 4140 alloy steel was radiated by a diode laser to give surface temperatures in the range between 600 and 800°C, and subsequently underwent vibration peening. The fatigue behavior of surface-treated specimens was examined using a giga-cycle ultrasonic fatigue test, and it was compared with that of non-treated and only-peened specimens. Fatigue fractured surfaces and microstructural evolution with respect to the laser treatment temperatures were investigated using an optical microscope. Hardness distribution was measured using Vickers micro-hardness. Higher laser temperature resulted in higher fatigue strength, attributed to the phase transformation.

Effect of Post Weld Heat Treatment on Al 5052-SS 316 Explosive Cladding with Copper Interlayer

2018 ◽  
Vol 910 ◽  
pp. 35-40
Author(s):  
Eswaran Elango ◽  
Somasundaram Saravanan ◽  
Krishnamorthy Raghukandan
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Intermetallic Compounds ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Post Weld Heat Treatment ◽  
Inclination Angles ◽  
Copper Interlayer ◽  
Weld Heat

This study focuses on effect of post weld heat treatment (PWHT) on interfacial and mechanical properties of Al 5052-SS 316 explosive clad with copper interlayer at varied loading ratios and inclination angles. The use of interlayer is proposed for the control of additional kinetic energy dissipation and to alleviate the formation of intermetallic compounds at the interface. The Al-Steel clads are subjected to PWHT at varied temperatures (300°C-450°C) for 30 minutes and the results are presented. The microstructural characterization of as-clad and PWHT samples is observed by an optical microscope and Scanning Electron Microscope (SEM). Maximum hardness is obtained at the interface of the as-clad and PWHT samples. Increase in PWHT temperature enhances the tensile strength of the composite, whereas, the tensile strength decreases at 300°C due to the diffusion of Al and Cu elements and the formation of detrimental intermetallic compounds.

Influence of heat input and solubilizing heat treatment on the impact properties of SAW joints in SAF 2205 duplex steel

2012 ◽  
Vol 1381 ◽  
Author(s):  
M. Merlin ◽  
R. Vazquez-Aguilar ◽  
C. Soffritti ◽  
A. Reyes-Valdes
Keyword(s):  
Heat Treatment ◽  
Heat Input ◽  
Welding Process ◽  
Optical Microscope ◽  
Image Analyzer ◽  
Secondary Phases ◽  
Impact Properties ◽  
Steel Joints ◽  
Saf 2205 ◽  
The Impact

ABSTRACTIn this study the influence of heat input (HI) and heat treatment on submerged arc welded duplex SAF 2205 steel joints has been evaluated. In particular, multi-pass welding operations have been performed on 18 mm thick plates using four different heat inputs; a post-weld solubilizing heat treatment has been carried out in order to reduce the microstructural effects on the structure of the heat affected zone (HAZ). Instrumented impact strength tests have been performed on Charpy samples machined from the welded joints; the total absorbed energy and the two complementary contributions of initiation and propagation energies have been evaluated and correlated to the percentages of ferrite and austenite. The microstructures and the fracture profiles have been observed using an optical microscope (OM) and quantitatively analyzed by means of an image analyzer. A scanning electron microscope (SEM) equipped by energy dispersive X-ray spectroscopy (EDS) has been used to study the fractured surfaces. Hardness profiles have been performed across the joints in order to verify the hardness variations. A total absence of secondary phases has been found on the joints due to the performing of a suitable solubilizing heat treatment after the welding process. The results have shown that the impact properties of the samples have been mostly affected by the different heat inputs; in some cases a partial welding penetration has been found.

Microstructural Characterization of Photoluminescent Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
J. M. Macaulay ◽  
F. M. Ross ◽  
P. C. Searson ◽  
S. K. Sputz ◽  
R. People ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Porous Silicon ◽  
Microstructural Characterization ◽  
Photoluminescence Spectroscopy ◽  
Experimental Results ◽  
Visible Luminescence ◽  
Wide Range ◽  
The Impact

ABSTRACTWe have used electron microscopy to examine the microstructure of porous silicon films over a wide range of doping levels, and photoluminescence spectroscopy to study their optical properties. We discuss the impact of our experimental results on models from the literature which were proposed to explain visible luminescence from porous silicon.

Microstructural characterization of a corrosion-resistant hydrotalcite coating on aluminum

1993 ◽  
Vol 51 ◽  
pp. 850-851
Author(s):  
C. A. Drewien ◽  
C. R. Hills ◽  
R. G. Buchheit
Keyword(s):  
Electrochemical Corrosion ◽  
Microstructural Characterization ◽  
Lithium Carbonate ◽  
Porous Network ◽  
Corrosion Resistant ◽  
Aluminum Lithium ◽  
Electrochemical Corrosion Behavior ◽  
Corrosion Resistant Coatings ◽  
The Impact

Aluminum-lithium-hydroxycarbonate hydrate (Li2Al4CO3(OH)12*3H2O) or hydrotalcite coatings are novel corrosion resistant coatings being considered for replacement of environmentally sensitive chromate conversion coatings. Hydrotalcite coatings provide corrosion protection to aluminum alloys used in atmospheric environments. In order to model the electrochemical corrosion behavior and to assess the impact of changing processing variables on the overall corrosion performance, a detailed baseline characterization of the microstructure was required.Hydrotalcite coatings were formed by immersion of an 1100 aluminum alloy into a room temperature, alkaline bath of lithium carbonate and lithium hydroxide for 15 minutes. Microstructural characterization of the coating was performed using both scanning (SEM) and transmission (TEM) electron microscopy. In Figure 1a, the secondary electron image of the surface, obtained on a JEOL 6400 SEM operated at 15 kV, reveals a porous network of hydrotalcite crystals oriented perpendicular to the plane of viewing. In order to determine whether the pores were continuous to the substrate and to provide further characterization, crosssectional TEM was performed.

Impurity-controlled contrast in secondary-electron images of reaction-bonded silicon carbide

1990 ◽  
Vol 48 (4) ◽  
pp. 888-889
Author(s):  
R.A. Youngman
Keyword(s):  
Secondary Electron ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
The Past ◽  
Contrast Mechanism ◽  
Backscattered Electron ◽  
In Situ Formation ◽  
Secondary Ion

Reaction-bonded SiC is formed by the high temperature (>2100°C) heat treatment of a mixture of alpha-SiC powder and organic binders in the presence of elemental Si. The bonding occurs by the in-situ formation of beta-SiC from the reaction of the pyrolyzed binder and the Si. Substantial microstructural characterization of these materials has been carried out in the past. A particular feature of these analyses is the so-called trace-impurity-controlled contrast of secondary electron (SE) images of uncoated specimens. This report describes further attempts to elucidate the origin of this contrast mechanism.Samples of reaction-bonded SiC (Hexoloy KT, The Carborundum Co.) were prepared for multiple-technique analysis. This was accomplished by preparing an optical thin section for reflected and transmitted optical microscopy. Regions of interest were diamond-scribed on the optical microscope (Leitz, Orthoplan) and then SE and backscattered electron (BE) microscopy (CamScan, Series IV) of the same areas (both coated and uncoated with evaporated carbon) was conducted. Finally, the same areas were imaged in a secondary ion mass spectrometer (SIMS) (Cameca, IMS3F) to detect trace and major impurity levels.

Microstructural Characterization of Aluminum-Carbon Nanotube Nanocomposites Produced Using Different Dispersion Methods

2016 ◽  
Vol 22 (3) ◽  
pp. 725-732 ◽  
Author(s):  
Sónia Simões ◽  
Filomena Viana ◽  
Marcos A. L. Reis ◽  
Manuel F. Vieira
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ball Milling ◽  
Electron Backscatter Diffraction ◽  
Microstructural Characterization ◽  
Single Step ◽  
Strengthening Effect ◽  
Transmission Electron ◽  
The Impact

AbstractThis research focuses on characterization of the impact of dispersion methods on aluminum-carbon nanotubes (Al-CNTs) nanocomposite structure. Nanocomposites were produced by a conventional powder metallurgy process after the dispersion of the CNTs on the Al powders, using two approaches: (1) the dispersion of CNTs and mixture with Al powders were performed in a single step by ultrasonication; and (2) the CNTs were previously untangled by ultrasonication and then mixed with Al powders by ball milling. Microstructural characterization of Al-CNT nanocomposites was performed by optical microscopy, scanning and transmission electron microscopy, electron backscatter diffraction, and high-resolution transmission electron microscopy (HRTEM). Microstructural characterization revealed that the use of ball milling for mixing CNTs with Al powders promoted the formation of CNT clusters of reduced size, more uniformly dispersed in the matrix, and a nanocomposite of smaller grain size. However, the results of HRTEM and Raman spectroscopy show that ball milling causes higher damage to the CNT structure. The strengthening effect of the CNT is attested by the increase in hardness and tensile strength of the nanocomposites.

Novel Method to Toughen Polypropylene by Uniaxial Compression Processing

2011 ◽  
Vol 239-242 ◽  
pp. 3249-3252 ◽  
Author(s):  
Ming Li Jiao ◽  
Kai Yang ◽  
Yan Chen
Keyword(s):  
Mechanical Properties ◽  
Uniaxial Compression ◽  
Impact Test ◽  
Small Deformation ◽  
Optical Microscope ◽  
Rapid Rise ◽  
Impact Properties ◽  
Novel Method ◽  
The Impact

Based on the orientation of molecule chain in fibers, it will urge a rapid increase in mechanical properties. Nevertheless, block materials mainly gain rise of mechanical properties by blend or composite today, it is hardly proposed on self-toughening materials by optimizing the microstructure because of a lack of relations between the performance and the microstructure in block materials. In this paper, a toughening PP was gained through small deformation of spherulite, processed by uniaxial compression. A series of measurements were applied, including impact test and polarizing optical microscope (POM). The results show that the impact properties of polypropylene (PP) have a rapid rise. POM suggests that the spherulite has deformed into ellipsoid even belt along the orientation of sample of PP, which plays an important role in toughening.

scholarly journals Physical Characterization of Bismuth Oxide Nanoparticle Based Ceramic Composite for Future Biomedical Application

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1626
Author(s):  
Pravin Jagdale ◽  
Gianpaolo Serino ◽  
Goldie Oza ◽  
Alberto Luigi Audenino ◽  
Cristina Bignardi ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Bismuth Oxide ◽  
Biomedical Application ◽  
Three Point Bending ◽  
Weight Losses ◽  
Bismuth Oxide Nanoparticles ◽  
Dispersion Media ◽  
Oxide Nanoparticle ◽  
The Impact

Employment and the effect of eco-friendly bismuth oxide nanoparticles (BiONPs) in bio-cement were studied. The standard method was adopted to prepare BiONPs-composite. Water was adopted for dispersing BiONPs in the composite. A representative batch (2 wt. % of BiONPs) was prepared without water to study the impact of water on composite properties. For each batch, 10 samples were prepared and tested. TGA (thermogravimetric analysis) performed on composite showed 0.8 wt. % losses in samples prepared without water whereas, maximum 2 wt. % weight losses observed in the water-based composite. Presence of BiONPs resulted in a decrease in depth of curing. Three-point bending flexural strength decreased for increasing BiONPs content. Comparative study between 2 wt. % samples with and without water showed 10.40 (±0.91) MPa and 28.45 (±2.50) MPa flexural strength values, respectively, indicating a significant (p < 0.05) increase of the mechanical properties at the macroscale. Nanoindentation revealed that 2 wt. % without water composites showed significant (p < 0.05) highest nanoindentation modulus 26.4 (±1.28) GPa and hardness 0.46 (±0.013) GPa. Usage of water as dispersion media was found to be deleterious for the overall characteristics of the composite but, at the same time, the BiONPs acted as a very promising filler that can be used in this class of composites.

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