scholarly journals Microstructural and Mechanical Studies of PVA Doped with ZnO and WO3 Composites Films

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
N. B. Rithin Kumar ◽  
Vincent Crasta ◽  
Rajashekar F. Bhajantri ◽  
B. M. Praveen
Keyword(s):  
Polymer Composites ◽  
Room Temperature ◽  
Testing Machine ◽  
Casting Method ◽  
Weight Percentage ◽  
Universal Testing ◽  
Percentage Concentration ◽  
Doped Polymer ◽  
Nanosized Zno ◽  
Mechanical Studies

Polymer composites of ZnO and WO3 nanoparticles doped polyvinyl alcohol (PVA) matrix have been prepared using solvent casting method. The microstructural properties of prepared films were studied using FTIR, XRD, SEM, and EDAX techniques. In the doped PVA, many irregular shifts in the FTIR spectra have been observed and these shifts in bands can be understood on the basis of intra/intermolecular hydrogen bonding with the adjacent OH group of PVA. The chemical composition, phase homogeneity, and morphology of the polymer composites of the polymer film were studied using EDAX and SEM. These data indicate that the distribution of nanosized ZnO and WO3 dopants is uniform and confirm the presence of ZnO and WO3 in the film. The crystal structure and crystallinity of polymer composites were studied by XRD. It was found that the change in structural repositioning and crystallinity of the composites takes place due to the interaction of dopants and also due to complex formation. The mechanical studies of doped polymer films were carried out using universal testing machine (UTM) at room temperature, indicating that the addition of the ZnO and WO3 with weight percentage concentration equal to 14% increases the tensile strength and Young’s modulus.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

The Effects of Winding Angles and Elevated Temperatures on the Crushing Behaviour of Glass Fibre/Epoxy Composite Pipes

2014 ◽  
Vol 695 ◽  
pp. 639-642
Author(s):  
S.N. Fitriah ◽  
M.S. Abdul Majid ◽  
R. Daud ◽  
Mohd Afendi
Keyword(s):  
Compressive Strength ◽  
Glass Fibre ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Universal Testing ◽  
Glass Fibre Reinforced ◽  
Crushing Behavior ◽  
Composite Pipes ◽  
Winding Angle

The paper discusses the crushing behavior of various winding angles of glass fibre reinforced epoxy (GRE) pipes at elevated temperatures. Two different winding angles of composite pipes were chosen for the study; ± 55°, ± 63°. GRE pipes angled ± 55° and ± 63° are compressed using Universal Testing Machine (UTM) at room temperature and elevated temperatures of 45°C, 65°C, and 95°C according to ASTM D695-10 standard. The temperatures were chosen based on the glass transition temperature (Tg) that was measured earlier. The results show that as the temperature is increased, the compressive strength significantly degraded. This is due to the change in the properties of the GRE pipe from a rigid state to a more rubbery state as the composite pipe reached Tg. GRE pipe with winding angle ± 55° show a higher compressive strength compared to ± 63°.

scholarly journals Comparative study of conventionally sintered Co-Ni-Al alloy with spark plasma sintered alloy

2018 ◽  
Vol 50 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Arputhavalli Johnsy ◽  
S. Agilan ◽  
M. Dinesh ◽  
S.J. Vijay ◽  
Roy Johnson
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Al Alloy ◽  
Sintered Alloy ◽  
Stoichiometric Ratio ◽  
Vibrating Sample Magnetometer ◽  
Universal Testing ◽  
Spark Plasma ◽  
Pin On Disk ◽  
Mechanical Studies

Co-Ni-Al alloy samples were prepared by compacting the powdered alloy at various pressures in proper stoichiometric ratio and the high density compacted alloy was sintered at 673 K. The magnetic, mechanical properties, microstructure and phase analysis were studied and compared with that of spark plasma sintered (SPS) alloy. The sintered alloy exhibit martensitic twin variants with ? phase structure. Along with the diffused particle, few agglomerated clusters were observed on the topographic images. The magnetic and the mechanical studies of the test specimens were investigated using the vibrating sample magnetometer, pin on disk tribometer and universal testing machine respectively. The coercivity value and the ductility of the SPS alloy are higher than the same of the as-sintered alloy.

A STUDY OF STRESS RELAXATION RATE IN UN-IRRADIATED AND NEUTRON-IRRADIATED STAINLESS STEEL

2007 ◽  
Vol 21 (05) ◽  
pp. 295-301 ◽  
Author(s):  
I. M. GHAURI ◽  
NAVEED AFZAL ◽  
N. A. ZYREK
Keyword(s):  
Stainless Steel ◽  
Stress Relaxation ◽  
Relaxation Rate ◽  
Room Temperature ◽  
Tensile Deformation ◽  
Testing Machine ◽  
Universal Testing ◽  
Radiation Induced ◽  
Stress Dependent ◽  
Induced Defects

Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2–12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining was frequently interrupted by arresting the cross head to observe stress relaxation at fixed load. Stress relaxation rate, s, was found to be stress dependent i.e. it increased with increasing stress levels σ0 both in un-irradiated and irradiated specimens, however the rate was lower in irradiated specimens than those of un-irradiated ones. A further decrease in s was observed with increase in exposure time. The experiential decrease in the relaxation rate in irradiated specimens is ascribed to strong interaction of glide dislocations with radiation induced defects. The activation energy for the movement of dislocations was found to be higher in irradiated specimens as compared with the un-irradiated ones.

Research on the Mechanical Performance of Magnesium Hydroxide Whiskers/Polymer Composites

2013 ◽  
Vol 826 ◽  
pp. 228-232
Author(s):  
Yu Zhi Jiang ◽  
Zhong Yang Zhang ◽  
Li Hua Wang
Keyword(s):  
Mechanical Properties ◽  
Polymer Composites ◽  
Magnesium Hydroxide ◽  
Mechanical Performance ◽  
Testing Machine ◽  
Sodium Stearate ◽  
Enhancement Effect ◽  
Universal Testing ◽  
Mechanics Performance ◽  
Engineering Plastics

The modified and unmodified magnesium hydroxide whiskers (MH) were mixed with PE, PP, ABS matrix respectively. The mechanics performance of MH/polymer composites was tested by the universal testing machine. The effect of modified and unmodified MH whiskers addition on the performance of composite material mechanics was studied. The results show that the whiskers modified by sodium stearate had a significant mechanical improvement to the MH/PE, MH / PP and MH/ABS composites than unmodified whiskers. The content of modified MH whiskers added to PE, PP, ABS matrix materials are different when the best comprehensive mechanical properties are obtained, which are 20%20% and 40% respectively. Overall, the modified MH whiskers had a significant enhancement effect on the general plastics and engineering plastics.

scholarly journals Flexural Strength of E-glass-reinforced PMMA

2014 ◽  
Vol 3 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Merin Mathew ◽  
Kamalakanth Shenoy ◽  
KS Ravishankar
Keyword(s):  
Flexural Strength ◽  
Glass Fiber ◽  
Microstructural Analysis ◽  
Testing Machine ◽  
Weight Percentage ◽  
Monomer Ratio ◽  
Universal Testing ◽  
Detailed Statistical Analysis ◽  
One Way Anova

ABSTRACT Background Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterials due to its acceptable advantageous but the limitations associated with these materials make them far from being ideal. So, the present study is to achieve desirable flexural strength by reinforcing PMMA with E-glass fiber. Aim Determination of flexural strength of PMMA by varying the weight percentage of glass fiber (2.5 wt%, 5 wt%, 10 wt%), and by varying the aspect ratio (3 mm/20 µm, 6 mm/20 µm, 12 mm/20 µm) of glass fiber. Materials and methods Specimens prepared using a standard rectangular mold of 62 mm length, 10 mm breadth and 2.5 mm thickness. A total of 60 samples prepared (6 samples in each group) polymer—monomer ratio 2.4:1 by weight used to prepare samples. Flexural strength is tested using universal testing machine Instron. The microstructural analysis using scanning electron microscopy performed in order to understand the fiber matrix bonding. Detailed statistical analysis done by one-way ANOVA. Results Highest flexural strength is observed for the PMMA reinforced with 6 mm/20 µm fiber 2.5 wt%. How to cite this article Mathew M, Shenoy K, Ravishankar KS. Flexural Strength of E-glass-reinforced PMMA. Int J Experiment Dent Sci 2014;3(1):24-28.

scholarly journals Effect of Stirring Speed and Stirring Time on Distribution of Nano Al2O3 Particles in Al7075 Metal Matrix Composite

2019 ◽  
Vol 8 (2) ◽  
pp. 86-89
Author(s):  
H. P. Raju ◽  
M. S. Prashanth Reddy
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Mixing Time ◽  
Testing Machine ◽  
Hardness Test ◽  
Processing Parameters ◽  
Stir Casting ◽  
Casting Method ◽  
Universal Testing ◽  
Stirring Time

Al7075 was successfully synthesized with the addition of Nano Al2O3 with 1.00Wt% by stir casting method by considering various stirring speeds and stirring times during this study. Scanning Electron Microscopy (SEM) is adapted to examine the microstructure of prepared composites. Tensile strength are tested on composite specimens (as per ASTM E8M-09) using computerized Universal Testing Machine (UTM). Micro Vicker’s hardness test was carried out on top of the polished composite specimens. The results showed the microstructure, ultimate tensile strength and hardness of the composite were influenced by the stirring speed and stirring time. From the microstructure it is revealed that, the particle clustering was more at a lower stirring speed with a lower stirring time. Increased mixing speed and mixing time resulted in better particle distribution. The results of the hardness test also demonstrated that, the composite’s hardness is affected by the stirring speed and time. At 400 rpm with a stirring time of 10 minutes, the uniform hardness levels are achieved. But the properties degraded again after an interval of certain time. Present study is conducted to determine microstructure, ultimate tensile strength, and hardness of composite and the tendency between processing parameters such as stirring speed and time.

Effect of Repeated Preheating Cycles on Flexural Strength of Resin Composites

2013 ◽  
Vol 38 (1) ◽  
pp. 33-38 ◽  
Author(s):  
M D'Amario ◽  
S Pacioni ◽  
M Capogreco ◽  
R Gatto ◽  
M Baldi
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Testing Machine ◽  
Bending Test ◽  
Resin Composites ◽  
Control Groups ◽  
Three Point Bending ◽  
Universal Testing ◽  
Group A ◽  
Significant Factors

SUMMARY The aim of this study was to assess the flexural strengths of three resin composites prepared at room temperature or cured after 20 or 40 cycles of preheating to a temperature of 45°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium) (HFO), Enamel Plus HRi (Micerium) (HRi), Opallis + (FGM) (OPA). One group of specimens for each composite was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 20 or 40 preheating cycles to a temperature of 45°C in a preheating device. Ten specimens were prepared for each group. A three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with a two-way analysis of variance (ANOVA) test and a Games-Howell test (α = 0.05). The two-way ANOVA showed that both the material and the number of heating cycles were significant factors, able to influence the flexural strength values (p<0.05). However, there was not a statistically significant interaction (p>0.05). For all three composites flexural strengths were not affected after 20 preheating cycles in comparison with the control groups (0 preheating cycles) but were, however, significantly decreased when 40 prewarming cycles were conducted. The HRi and OPA groups had the highest flexural strengths, with no statistically significant differences among them. HFO presented significantly lower flexural strengths in comparison with HRi.

Experimental Investigation on Mechanical Properties of Wheat Husk Pulp Rein Forced Epoxy Composites

2020 ◽  
Vol 36 ◽  
pp. 114-125
Author(s):  
Kanwal Jit Singh ◽  
Rohit Kumar ◽  
Ramratan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Testing Machine ◽  
Weight Percentage ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
The Impact ◽  
Wheat Husk

The wheat husk pulp epoxy resin composites were prepared by compression Molding Method and their physical and Mechanical Properties were studied by universal testing Machine. The composites were tested by tensile strength testing and impact strength tester. The content of Wheat husk pulp is varied (35%, 45%, 55%) weight percentage whereas the epoxy resin is varied (50%, 40%, 30%) percentage is kept constant 15% in hardener. Composites have been fabricated using hand layup technique using a suitable mold developed in industry. All the sample have been tested in Universal testing machine as per ASTM standard for tensile strength and impact strength it is observed that composite with 35% wheat husk pulp is having highest tensile strength of 4mm (4.29MPa) and 8mm (6.31Mpa). The impact strength of Composite with 35% wheat husk pulp was highest than 35%to 45% wheat husk pulp.

STRESS RELAXATION BEHAVIOR OF IRRADIATED COPPER IN THE TEMPERATURE RANGE 150–300 K

2009 ◽  
Vol 23 (04) ◽  
pp. 655-660
Author(s):  
I. M. GHAURI ◽  
NAVEED AFZAL ◽  
NAWAZ MUHAMMAD ◽  
SAJJAD AHMED
Keyword(s):  
Electron Beam ◽  
Stress Relaxation ◽  
Relaxation Rate ◽  
Room Temperature ◽  
Testing Machine ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Temperature Range ◽  
Universal Testing ◽  
Dislocation Defects

The present study reports the stress relaxation behavior of irradiated polycrystalline 5N copper deformed in the temperature range 150 to 300 K. The wire specimens were exposed to an 18 MeV electron beam at room temperature and stress relaxation tests of the specimens were carried out during the tensile test, using universal testing machine between 150 to 300 K. Stress relaxation rate of the specimens was found to decrease with the decrease of test temperature. The decrease of the stress relaxation rate with temperature in irradiated specimens is attributed to the dislocation-defects interaction, which is more pronounced at low temperature due to the reduction in available thermal energy necessary for the relaxation of dislocations.

Sign in / Sign up

Export Citation Format

Share Document