Effect of TiO2 nanoparticles on the viscoelastic and time-dependent behaviors of TiO2/epoxy particulate nanocomposite

2017 ◽  
Vol 37 (2) ◽  
pp. 185-196 ◽  
Author(s):  
Hamid Reza Salehi ◽  
Manouchehr Salehi
Keyword(s):  
Epoxy Resin ◽  
Storage Modulus ◽  
Creep Resistance ◽  
Epoxy Resins ◽  
Loss Modulus ◽  
Tensile Creep ◽  
Titania Nanoparticles ◽  
Test Machine ◽  
Creep Tests ◽  
Mechanical Creep

Abstract In this work, the effects of nano titania are investigated on mechanical, creep, and viscoelastic behaviors of epoxy resin. For this purpose, 0.25, 0.5, and 1 vol.% of TiO2 nanoparticles were mixed with thermoset epoxy resin by mechanical and ultrasonic homogenizers and then the tensile, creep, and DMTA test samples were fabricated. The results of tensile tests show that the addition of TiO2 nanopowder slightly increased the strength and Young’s modulus of epoxy resin. However, the ultimate tensile strain or the rupture strain of nanocomposites is decreased. In addition, to understand the viscoelastic behavior of nanocomposites, the DMTA and tensile creep tests have been done. Tensile creep test has been done by DMTA and universal test machine. Both results confirmed that the creep resistance of nanocomposites has extensively improved by adding the titania nanoparticles. Variations of storage modulus, loss modulus, and tan (δ) by adding TiO2 nanopowder were examined in two modes of bending and tension. Storage and loss moduli of nanocomposite are considerably increased in all the states, but the storage modulus was more sensitive to TiO2 loading intensity. Thus, test results showed that introduction of TiO2 in the epoxy resin leads to the improvement of mechanical, creep resistance, and viscoelastic properties of nanocomposites. Due to the wide applications of epoxy resins in engineering devices, this method of reinforcement can be practical and useful to overcome some limitations of epoxy resins.

The Creep Behaviors of Two Fine-grained XD TiAl Alloys Produced by Similar Heat Treatments

2004 ◽  
Vol 842 ◽  
Author(s):  
Hanliang Zhu ◽  
Dongyi Seo ◽  
Kouichi Maruyama ◽  
Peter Au
Keyword(s):  
Grain Boundaries ◽  
Creep Resistance ◽  
Lamellar Spacing ◽  
Heat Treatments ◽  
Tensile Creep ◽  
Microstructural Stability ◽  
Creep Tests ◽  
Tial Alloys ◽  
Fine Grained ◽  
Interlocked Grain

ABSTRACTThe microstructural characteristics and creep behavior of two fine-grained XD TiAl alloys, Ti-45Al and 47Al–2Nb–2Mn+0.8vol%TiB2 (at%), were investigated. A nearly lamellar structure (NL) and two kinds of fully lamellar (FL) structures in both alloys were prepared by selected heat treatments. The results of microstructural examination and tensile creep tests indicate that the 45XD alloy with a NL structure possesses an inferior creep resistance due to its coarse lamellar spacing and larger amount of equiaxed γ grains at the grain boundaries, whereas the same alloy in a FL condition with fine lamellar spacing lowers the minimum creep rates. Contrary to 45XD, the 47XD alloy with a NL structure exhibits the best creep resistance. However, 47XD with a FL structure with finer lamellar spacing shows inferior creep resistance. On the basis of microstructural deformation characteristics, it is suggested that the well-interlocked grain boundary and relatively coarse colony size in FL and NL 47XD inhibit sliding and microstructural degradation at the grain boundaries during creep deformation, resulting in better creep resistance. Therefore, good microstructural stability is essential for improving the creep resistance of these alloys.

Effect of Fiber Volume Fraction on High Temperature Creep of Al2O3-SiO2(sf)/AZ91D Composite

2011 ◽  
Vol 474-476 ◽  
pp. 548-552
Author(s):  
Jun Tian
Keyword(s):  
Creep Resistance ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Matrix Alloy ◽  
Short Fiber ◽  
Tensile Creep ◽  
Short Fibers ◽  
Creep Tests ◽  
Fiber Volume ◽  
The Matrix

Constant stress tensile creep tests were conducted on AZ91D–20 vol.%, 25 vol.%, and 30 vol.% Al2O3-SiO2short fiber composites and on an unreinforced AZ91D matrix alloy. The creep resistance of the reinforced materials is shown to be considerably improved compared with the matrix alloy. With the increasing volume fraction of short fibers, the creep resistance of AZ91D composites is improved, and their creep threshold stresses are also increased accordingly. Because of the increasing volume fraction of short fibers, loads of bearing and transmission of short fibers will increase, and thus the creep resistance of AZ91D composites further improves, but the precipitation of β-Mg17Al12precipitate increases in the number, it is easy to soften coarse, so that threshold stress of AZ91D composite does not increase greatly.

REACTIVE COMPATIBILIZATION OF THE BLENDS OF THERMOPLASTIC POLYURETHANE AND POLYDIMETHYLSILOXANE RUBBER

2015 ◽  
Vol 88 (4) ◽  
pp. 584-603 ◽  
Author(s):  
Jineesh Ayippadath Gopi ◽  
Golok Bihari Nando
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Thermoplastic Polyurethane ◽  
Domain Size ◽  
Damping Factor ◽  
Creep Tests ◽  
Dynamic Mechanical ◽  
Compatibilization Effect ◽  
Compatibilized Blends

ABSTRACT The effect of ethylene-co-methacrylate (EMA) as polymeric chemical compatibilizer on the mechanical, dynamic mechanical, phase morphology, adhesion, and rheological properties of the blends of thermoplastic polyurethane (TPU)–polydimethylsiloxane rubber (PDMS) was investigated at different blend ratios. Melt blending technique was used to prepare the compatibilized blends. Enhancement of the mechanical properties and the reduction of dispersed PDMS domain size in the alloy confirmed the compatibilization effect of EMA on TPU-PDMS blends. Dynamic mechanical properties such as storage modulus, loss modulus, and the damping factor were evaluated to assess the compatibilization effect of EMA on TPU-PDMS blends. Creep tests revealed that compatibilization led to better dimensional stability. Compatibilized blends with finer PDMS rubber domains showed relatively less reduction in storage modulus as compared with uncompatibilized blends during stress relaxation studies. Rheological analysis suggested that the incorporation of EMA decreased the interfacial slip between the blend constituents, and this also confirmed the compatibilization effect of EMA on TPU-PDMS rubber blends as a polymeric reactive compatibilizer.

scholarly journals New Eco-Friendly Synthesized Thermosets from Isoeugenol-Based Epoxy Resins

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 229 ◽  
Author(s):  
Quentin Ruiz ◽  
Sylvie Pourchet ◽  
Vincent Placet ◽  
Laurent Plasseraud ◽  
Gilles Boni
Keyword(s):  
Epoxy Resin ◽  
Storage Modulus ◽  
Epoxy Resins ◽  
Diglycidyl Ether ◽  
Thermal And Mechanical Properties ◽  
Optimum Ratio ◽  
Structural Composites ◽  
Molar Ratios ◽  
Elemental Analyses ◽  
Dsc Analyses

Epoxy resin plays a key role in composite matrices and DGEBA is the major precursor used. With the aim of favouring the use of bio resources, epoxy resins can be prepared from lignin. In particular, diglycidyl ether of isoeugenol derivatives are good candidates for the replacement of DGEBA. This article presents an effective and eco-friendly way to prepare epoxy resin derived from isoeugenol (BioIgenox), making its upscale possible. BioIgenox has been totally characterized by NMR, FTIR, MS and elemental analyses. Curing of BioIgenox and camphoric anhydride with varying epoxide function/anhydride molar ratios has allowed determining an optimum ratio near 1/0.9 based on DMA and DSC analyses and swelling behaviours. This thermoset exhibits a Tg measured by DMA of 165 °C, a tensile storage modulus at 40 °C of 2.2 GPa and mean 3-point bending stiffness, strength and strain at failure of 3.2 GPa, 120 MPa and 6.6%, respectively. Transposed to BioIgenox/hexahydrophtalic anhydride, this optimized formulation gives a thermoset with a Tg determined by DMA of 140 °C and a storage modulus at 40 °C of 2.6 GPa. The thermal and mechanical properties of these two thermosets are consistent with their use as matrices for structural or semi-structural composites.

Creep Behavior of an AZ91 Magnesium Alloy Reinforced with Aluminum Silicate Short Fibers

2010 ◽  
Vol 97-101 ◽  
pp. 492-495 ◽  
Author(s):  
Jun Tian ◽  
Wen Fang Li ◽  
Li Fa Han ◽  
Ji Hua Peng
Keyword(s):  
Creep Resistance ◽  
Fiber Composite ◽  
Matrix Alloy ◽  
Grain Boundary Sliding ◽  
Tensile Creep ◽  
Aluminum Silicate ◽  
Short Fibers ◽  
Az91 Magnesium Alloy ◽  
Creep Tests ◽  
The Matrix

Constant stress tensile creep tests were conducted on an AZ 91–25 vol.% aluminum silicate short fiber composite and on an unreinforced AZ 91 matrix alloy. The creep resistance of the composite is shown to be considerably improved compared with the matrix alloy, and the resistance effect is better with the increase of temperature. The steady-state creep rate of the composite is 4.54% of matrix alloy at 473K, and 2.56% of matrix alloy at 573K. The creep strengthening arises mainly from the effective load transfer between plastic flow in the matrix and the fibers. Microstructural investigations by SEM revealed good fiber–matrix interface bonding during creep exposure. Short fibers have a great function in load bearing and transmission load, and greatly hinder the dislocation movement, thus enhancing the creep resistance of the composite. The creep mechanism of the composite is dislocation and grain boundary sliding control.

scholarly journals Influence of High Pressure Sliding and Rotary Swaging on Creep Behavior of P92 Steel at 500 °C

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2044
Author(s):  
Petr Kral ◽  
Jiri Dvorak ◽  
Vaclav Sklenicka ◽  
Zenji Horita ◽  
Yoichi Takizawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Creep Resistance ◽  
Equivalent Strain ◽  
Creep Testing ◽  
Tensile Creep ◽  
Initial Stresses ◽  
Coarse Grained ◽  
Creep Tests ◽  
P92 Steel ◽  
Rotary Swaging

High-pressure sliding (HPS) and rotary swaging (RS) at room temperature were used to form severely deformed microstructures in martensitic creep-resistant P92 steel. The deformed microstructures contained markedly different ratios of low- and high-angle grain boundaries (LAGBs/HAGBs). The application of the RS method, with an imposed equivalent strain of 1.4, led to the formation of a heterogeneous microstructure with a high number of LAGBs, while the HPS method, with an imposed equivalent strain of 7.8, led to the formation of a relatively homogeneous ultrafine-grained microstructure with a significant predominance of HAGBs. Microstructure analyses after creep testing showed that the microstructure of RS- and HPS-processed P92 steel is quite stable, but a slight coarsening of subgrains and grains during creep testing can be observed. Constant load tensile creep tests at 500 °C and initial stresses ranging from 300 to 900 MPa revealed that the specimens processed by HPS exhibited higher creep strength (slower minimum creep rate) and ductility compared to the coarse-grained and RS-processed P92 steel. However, the HPS-processed P92 steel also exhibited lower values of stress exponent n than the other investigated states of P92 steel. For this reason, the differences in minimum creep rates determined for different states decrease with decreasing values of applied stress, and at applied stresses lower than 500 MPa, the creep resistance of the RS-processed state is higher than the creep resistance of the HPS-processed state.

scholarly journals Study on creep perform of epoxy resin for launch canister

2021 ◽  
Vol 2125 (1) ◽  
pp. 012054
Author(s):  
Fu-Quan Wei ◽  
Wen-chao Yang ◽  
Zhe-xian Zhan ◽  
Cun-gui Yu
Keyword(s):  
Epoxy Resin ◽  
Matrix Material ◽  
Element Model ◽  
Tensile Creep ◽  
Creep Model ◽  
Resin Matrix ◽  
Model Parameters ◽  
Test Results ◽  
Creep Tests ◽  
Term Creep

Abstract In order to study the creep perform of the launch canister, creep perform of the epoxy resin (matrix material) were studied. The creep model of epoxy resin was established based on Bailey-Norton model. Constant stress tensile creep tests at room temperature were carried out on epoxy resin specimens under different stress levels, and the model parameters were obtained by fitting the test data. The finite element model of the specimen was established in the ABAQUS software and the tensile simulation was carried out. The simulation results are consistent with the test results. Results show that time-hardening model can describe the short-term creep perform of epoxy resin with error less than 20%.

Epoxy Resin Embedment

1968 ◽  
Vol 26 ◽  
pp. 100-101
Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Light Microscope ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Tissue Preservation ◽  
Resin System ◽  
Excellent Quality

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

An Experimental and Modeling Investigation of Tensile Creep Resistance in a Stable Nanocrystalline Alloy

2020 ◽  
Author(s):  
C. Kale ◽  
S. Srinivasan ◽  
B.C. Hornbuckle ◽  
R.K. Koju ◽  
K. Darling ◽  
...  
Keyword(s):  
Creep Resistance ◽  
Nanocrystalline Alloy ◽  
Tensile Creep
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