scholarly journals The Degradation of Mechanical Properties in Halloysite Nanoclay-Polyester Nanocomposites Exposed in Seawater Environment

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Mohd Shahneel Saharudin ◽  
Jiacheng Wei ◽  
Islam Shyha ◽  
Fawad Inam
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Flexural Modulus ◽  
Resin Matrix ◽  
Matrix Interface ◽  
Sem Images ◽  
Plasticization Effect ◽  
Polyester Matrix ◽  
Seawater Environment ◽  
The Impact

Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nanocomposites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nanoclay-polyester nanocomposites. Results confirmed that the addition of halloysite nanoclay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nanoclay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease). Young’s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease). The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease). The impact toughness dropped from 0.71 kJ/m2to 0.48 kJ/m2(32% decrease). Interestingly, the fracture toughnessKICincreased with the addition of halloysite nanoclay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nanoclay-matrix interface influenced by seawater absorption and agglomeration of halloysite nanoclay.

Diallyl Orthophthalate(DAOP) Resin as a Reactive Plasticizer for Optimizing Glass-fiber/PVC Interface and Reactive Kinetics

2011 ◽  
Vol 239-242 ◽  
pp. 408-412 ◽  
Author(s):  
Peng Wen ◽  
Qi Lin Mei ◽  
Xiao Qin Yue ◽  
Meng Xin Liu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Toughness ◽  
Glass Fiber ◽  
Bending Strength ◽  
Sem Images ◽  
Melt Compounding ◽  
The Impact

To improve brittleness and optimize interface of glass-fiber/PVC composites, reinforcing and toughening technologies for glass-fiber/PVC composites were studied. Influences of glass-fiber and diallyl orthophthalate(DAOP) resin on their mechanical properties were observed. Diallyl orthophthalate(DAOP) resin was blended with PVC in various weight ratios by melt compounding. The compatibility between diallyl orthophthalate(DAOP) resin and PVC resin was analysed by measuring the impact toughness, tensile strength and bending strength. The results clarified that each mechanical properties improved, in addition to,SEM images show that the interface of glass-fiber/PVC composites added with DAOP was much closer , PVC resin surrounds completely the glass-fiber.

Effects of Seawater Immersion on Mechanical Properties of CFRP Composites

2013 ◽  
Vol 785-786 ◽  
pp. 209-213
Author(s):  
Qi Zhong Huang ◽  
Zhao Hui Hu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Resin Matrix ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Fiber Matrix Interface

Water absorption behavior and mechanical properties variation of the carbon fiber reinforced epoxy matrix composites (CFRP) immersed into artificial seawater were investigated by experiments. The rate of water absorption of the composite specimens is gradually reducing as the duality of immersion increasing. Due to the reversible and irreversible changes in the resin matrix and the failure of the fiber/matrix interface, the tensile strength, the flexural strength, and the ILSS of the composite specimens after 70 days immersion decreased 9.3%, 13%, and 17% respectively. And the tensile modulus and the flexural modulus the specimens after desorption were 83% and 70% of the original state, respectively

scholarly journals Mechanical Characterization with Morphological Analysis of Dry Flower Waste Bio Filler Reinforced Epoxy Composite

2019 ◽  
Vol 8 (4) ◽  
pp. 4497-4501 ◽  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Morphological Analysis ◽  
Mechanical Characterization ◽  
Epoxy Composite ◽  
Flexural Modulus ◽  
Morphological Properties ◽  
Resin Matrix ◽  
Sem Images

Dry flower waste powder is incorporated in the Epoxy resin matrix to study the effect of the bio filler in Epoxy composites. Composite Specimens were prepared by using different volume fractions (0.4, 0.8, 0.12, 0.16, 0.20 v/v) of Dry flower waste bio powder in the Epoxy resin by hand layup method. Experiments were conducted to evaluate the mechanical properties such as Tensile Properties, Flexural properties and Impact strength of the epoxy composite. The results indicated that the bio filler had significant influence on the tensile and flexural modulus whereas tensile and flexural strength and impact strength of the composite are not significantly affected by the addition of the filler. Better mechanical properties were obtained at 12% v/v of Dry flower waste bio powder. Morphological properties were examined using the SEM images of tensile fractured specimen.

scholarly journals Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Strengthening Mechanism ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Resin Matrix ◽  
Element Analysis ◽  
Epoxy Resin Matrix ◽  
The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

Mechanical Properties of Equal-Channel Angular Extrusion-Processed Al-20Zn Alloy

2012 ◽  
Vol 445 ◽  
pp. 195-200
Author(s):  
Murat Aydin ◽  
Yakup Heyal
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Equal Channel Angular Extrusion ◽  
Considerable Change ◽  
Fatigue Properties ◽  
Dendritic Microstructure ◽  
Two Phase ◽  
Angular Extrusion ◽  
Alloy Increase ◽  
The Impact

The mechanical properties mainly tensile properties, impact toughness and high-cycle fatigue properties, of two-phase Al-20Zn alloy subjected to severe plastic deformation (SPD) via equal-channel angular extrusion (ECAE) using route A up to 2 passes were studied. The ECAE almost completely eliminated as-cast dendritic microstructure including casting defects such as micro porosities. A refined microstructure consisting of elongated micro constituents, α and α+η eutectic phases, formed after ECAE via route A. As a result of this microstructural change, mechanical properties mainly the impact toughness and fatigue performance of the as-cast Al-20Zn alloy increased significantly through the ECAE. The rates of increase in fatigue endurance limit are approximately 74 % after one pass and 89 % after two passes while the increase in impact toughness is 122 %. Also the yield and tensile strengths of the alloy increase with ECAE. However, no considerable change occurred in hardness and percentage elongation of the alloy. It was also observed that the ECAE changed the nature of the fatigue fracture characteristics of the as-cast Al-20Zn alloy.

Physical Simulation of Weldability of Weldox 1300 Steel

2013 ◽  
Vol 762 ◽  
pp. 551-555 ◽  
Author(s):  
Marek Stanislaw Węglowski ◽  
Marian Zeman ◽  
Miroslaw Lomozik
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Physical Simulation ◽  
High Strength ◽  
Parent Material ◽  
Cooling Time ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Transformation Diagrams ◽  
The Impact

In the present study, the investigation of weldability of new ultra-high strength - Weldox 1300 steel has been presented. The thermal simulated samples were used to investigate the effect of welding cooling time t8/5 on the microstructure and mechanical properties of the heat affected zone (HAZ). In the frame of these investigation the microstructure was studied by the light (LM) and transmission electron microscopies (TEM). It has been shown that the microstructure of the Weldox 1300 steel is composed of tempered martensite, and inside the laths the minor precipitations mainly V(CN) and molybdenum carbide Mo2C were observed. Mechanical properties of parent material were analysed by the tensile, impact and hardness tests. In details the influence of cooling time in the range of 2,5 - 300 s. on hardness, impact toughness and microstructure of simulated HAZ was studied by using welding thermal simulation test. The results show that the impact toughness and hardness decrease with the increase of t8/5 under the condition of a single thermal cycle in simulated HAZ. The continuous cooling transformation diagrams (CCT-W for welding conditions) of Weldox 1300 steel for welding purposes was also elaborated. The steel Weldox 1300 for cooling time in the range of 2,5 - 4 s showed martensite microstructure, for time from 4 s to 60 s mixture of martensite and bainite, and for longer cooling time mixture of ferrite, bainite and martensite. The results indicated that the weldability of Weldox 1300 steel is limited and to avoid the cold cracking the preheating procedure or medium net linear heat input should be used.

scholarly journals Influence of Vanadium on the Microstructure and Mechanical Properties of Medium-Carbon Steels for Wheels

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Pengfei Wang ◽  
Zhaodong Li ◽  
Guobiao Lin ◽  
Shitong Zhou ◽  
Caifu Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Grain Refinement ◽  
Carbon Steels ◽  
Precipitation Strengthening ◽  
Austenite Grain Size ◽  
Medium Carbon ◽  
Microstructure And Mechanical Properties ◽  
Medium Carbon Steels ◽  
The Impact

Steels used for high-speed train wheels require a combination of high strength, toughness, and wear resistance. In 0.54% C-0.9% Si wheel steel, the addition of 0.075 or 0.12 wt % V can refine grains and increase the ferrite content and toughness, although the influence on the microstructure and toughness is complex and poorly understood. We investigated the effect of 0.03, 0.12, and 0.23 wt % V on the microstructure and mechanical properties of medium-carbon steels (0.54% C-0.9% Si) for train wheels. As the V content increased, the precipitation strengthening increased, whereas the grain refinement initially increased, and then it remained unchanged. The increase in strength and hardness was mainly due to V(C,N) precipitation strengthening. Increasing the V content to 0.12 wt % refined the austenite grain size and pearlite block size, and increased the density of high-angle ferrite boundaries and ferrite volume fraction. The grain refinement improved the impact toughness. However, the impact toughness then reduced as the V content was increased to 0.23 wt %, because grain refinement did not further increase, whereas precipitation strengthening and ferrite hardening occurred.

Preparation and Mechanical Properties of Epoxy Resin Reinforced with Jeffamines-Grafted Carbon Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 553-556 ◽  
Author(s):  
Ling Fei Shi ◽  
Gang Li ◽  
Gang Sui ◽  
Xiao Ping Yang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Epoxy Resin ◽  
Photoelectron Spectroscopy ◽  
Epoxy Matrix ◽  
Resin Matrix ◽  
Mechanical And Thermal Properties ◽  
Time Dynamic ◽  
Multi Walled Carbon Nanotubes ◽  
The Impact

The increasing proliferation and application of advanced polymer composites requires higher and broader performance resin matrices. Poly(oxypropylene) with –NH2 end-groups has been widely used to toughen epoxy resins, but the strength of resin matrix may be reduced due to the addition of flexible segments in the crosslinking network. Carbon nanotubes (CNTs) have been paid more and more attention in recent years because of their superior thermal and mechanical properties. In this paper, CNTs grafted with Jeffamines T403 were used to simultaneously improve the reinforcement and toughening of an epoxy resin. The untreated multi-walled carbon nanotubes (u-MWNTs) were functionalized with amine groups according to three steps: carboxylation, acylation, and amidation. The f-MWNTs were characterized by Fourier transform infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS). The experimental results indicated that the T403 was grafted to the surface of MWCNTs. The mechanical and thermal properties of epoxy with f-MWNTs were investigated. The tensile and flexural strength increased by 7.77 % and 7.03 % after adding 0.5wt% f-MWCNTs without sacrificing the impact toughness. At the same time, dynamic mechanical thermal analysis (DMTA) showed that the glass transition temperature (Tg) of epoxy with f-MWNTs were increased. The fracture surface of epoxy with f-MWNTs was observed by scanning electron microscopy (SEM) to understand the dispersion of f-MWNTs in epoxy matrix and interfacial adhesion between f-MWNTs and epoxy matrix, which can be attributed to the strong interfacial bonding between f-MWNTs and epoxy resin.

Effect of Tempering Time on Microstructure and Mechanical Properties of SA738 Gr.B Steel

2021 ◽  
Vol 1016 ◽  
pp. 1739-1746
Author(s):  
Yan Mei Li ◽  
Shu Zhan Zhang ◽  
Zai Wei Jiang ◽  
Sheng Yu ◽  
Qi Bin Ye ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Impact Energy ◽  
Nuclear Power ◽  
Microstructure And Mechanical Properties ◽  
The Impact ◽  
Tempering Time

The effect of tempering time on the microstructure and mechanical properties of SA738 Gr.B nuclear power steel was studied using SEM, TEM and thermodynamic software, and its precipitation and microstructure evolution during tempering were clarified. The results showed that SA738 Gr.B nuclear power steel has better comprehensive mechanical properties after tempering at 650 °C for 1h. With the extension of the tempering time, M3C transformed into M23C6 with increasing size, which affected the yield strength and impact energy. When the tempering time is 8h ~ 10h, due to the transformation of M3C to M23C6, the composition of matrix around the carbide changed, causing the temperature of Ac1 dropped, forming twin-martensite which deteriorated the impact toughness of the steel.

Study on Weldablity of Dissimilar Steel between 16MnR and S31803

2011 ◽  
Vol 391-392 ◽  
pp. 768-772 ◽  
Author(s):  
Li Yang ◽  
Zhan Zhe Zhang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Impact Toughness ◽  
Weld Metal ◽  
Welded Joint ◽  
Optical Microscope ◽  
Dissimilar Steel ◽  
Austenite Content ◽  
Mechanical Properties And Corrosion ◽  
The Impact

The weldablity of dissimilar steel between 16MnR and S31803 was analyzed and researched. By means of optical microscope (OM), the microstructure of the weld joint was investigated, which is welded by tungsten inert gas arc backing welding (GTAW) and manual arc filling welding (SMAW). The mechanical properties and corrosion resistance of the welded joint was also tested and studied. Results indicate that austenite and acicular ferrite distribute uniformly in the weld metal, which strengths the toughness and ductility of the joint. The austenite content in weld is higher than that in over-heated zone of S31803.The SMAW joint structure is coarsening than that of GTAW and has more austenite content. It is also observed that there are a decarburization layer and a carbon-enriched zone nearby the fusion line. And very small amounts of the third phase of harmful metal phase are found in the fusion zone of S31803 side. The welded joint shows the excellent mechanical properties and corrosion resistance. The impact toughness of the weld metal is higher than in HAZ of 16MnR side, and the impact toughness at GTAW side and in HAZ is superior to the SMAW side.

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