Effect of Thermal Aging on Mechanical Properties of EPDM Rubber

2015 ◽  
Vol 727-728 ◽  
pp. 318-321 ◽  
Author(s):  
Jie Liu ◽  
Lun Wu Zhang ◽  
Bin Wang ◽  
Ze Qi Xu ◽  
Wan Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Thermal Aging ◽  
Crosslink Density ◽  
Aging Process ◽  
Epdm Rubber ◽  
Compressive Testing ◽  
Scanning Electron ◽  
Accelerated Thermal Aging

EPDM rubber was exposed to an accelerated thermal aging environment produced by an air-circulating oven. The changes of morphology, mechanical properties of EPDM were monitored by scanning electron microscope (SEM), tensile/compressive testing. Crosslink density of EPDM was measured by the solvent swell method. The results showed that many cracks and voids appeared on the surface of EPDM with the exposure time. The aging process proceeded predominantly via crosslinking. The tensile strength increased with increase in crosslink density up to a maximum and thereafter decreased with further increase in crosslink density.

Effect of Functionalized MWCNT on the Mechanical and Dielectric Properties of PMMA Nanocomposites

2018 ◽  
Vol 18 (06) ◽  
pp. 1850035
Author(s):  
Punyapriya Mishra ◽  
Narasingh Deep ◽  
Sagarika Pradhan ◽  
Vikram G. Kamble
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Dielectric Properties ◽  
Conductive Polymer ◽  
Mechanical Tests ◽  
Surface Structures ◽  
Scanning Electron

Carbon nanotubes (CNTs) are widely explained in fundamental blocks of nanotechnology. These CNTs exhibit much greater tensile strength than steel, even almost similar to copper, but they have higher ability to carry much higher currents, they seem to be a magical material with all these mentioned properties. In this paper, an attempt has been made to incorporate this wonder material, CNT, (with varying percentages) in polymeric matrix (Poly methyl methacrylate (PMMA)) to create a new conductive polymer composite. Various mechanical tests were carried out to evaluate its mechanical properties. The dielectric properties such as dielectric loss and dielectric constant were evaluated with the reference of temperature and frequency. The surface structures were analyzed by Scanning Electron Microscope (SEM).

scholarly journals Mechanical Properties of Sigma 1140+ Sic Fibres Prior and after Composite Processing

2000 ◽  
Vol 9 (4) ◽  
pp. 096369350000900 ◽  
Author(s):  
C. Gonzalez ◽  
J. Llorca
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Elastic Modulus ◽  
Weibull Modulus ◽  
Fibre Diameter ◽  
Tensile Tests ◽  
Fibre Strength ◽  
Composite Processing ◽  
Scanning Electron

The effect of processing on the mechanical properties of Sigma 1140+ SiC fibres was studied through tensile tests carried out on pristine Sigma 1140+ SiC fibres and on fibres extracted from a Ti-6A1-4V-matrix composite. The elastic modulus and the tensile strength were computed after measuring carefully the fibre diameter. The characteristic fibre strength was reduced by 20% and the Weibull modulus by half during composite processing. The analysis of the fracture surfaces in the scanning electron microscope showed that the strength-limiting defects were located around the tungsten core in pristine fibres and predominantly at the surface in fibres extracted from the composite panels. These latter defects were nucleated by the mechanical stresses generated on the fibres during the panel consolidation.

Effect of Mo and Bi on Mechanical Properties of Zr-Fe-Cr Alloy at Room Temperature

2013 ◽  
Author(s):  
B. F. Luan ◽  
L. Q. Yang ◽  
T. G. Wei ◽  
K. L. Murty ◽  
C. S. Long ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Microstructure Observation ◽  
Scanning Electron ◽  
Zr Alloy

To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.

Study of Microstructure and Mechanical Properties of Extrued Spray Forming Al-8.5Fe-1.3V-1.7Si Alloy

2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Yield Strength ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
Extrusion Process ◽  
Spray Forming ◽  
Microstructure And Mechanical Properties ◽  
Scanning Electron

In this paper, the Al-8.5Fe-1.3V-1.7Si alloys were fabricated by spray forming and extrusion process. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that the tensile strength of the extrued alloys can reach 353MPa, the yield strength 300MPa, elongation 19.12%, at room temperature. At 250°C, the tensile strength of the extrued alloys can reach 221MPa, the yield strength 208MPa, elongation 13.33%.

scholarly journals Experiment on Strength and Failure Behavior of Sandstone Containing Pre-Existing Cracks Under Brazilian Compression

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Process ◽  
Experimental Results ◽  
Failure Behavior ◽  
Axial Deformation ◽  
Scanning Electron

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.

Hydroscopic and Mechanical Properties Performance Analysis of Rice Husk Powder/PLA Composites

2011 ◽  
Vol 230-232 ◽  
pp. 1231-1235 ◽  
Author(s):  
Jin Hua ◽  
Zhi Min Zhao ◽  
Wei Yu ◽  
Ben Zheng Wei
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Material ◽  
Lactic Acid ◽  
Electron Microscope ◽  
Rice Husk ◽  
Coupling Agent ◽  
Melt Blending ◽  
Water Absorbability ◽  
Scanning Electron

The rice husk powder was modified by polymer (lactic acid) (PLA) and Maleic anhydride (coupling agent, MAPP). Composite material was prepared in the way of melt blending. The mechanical properties, water absorbability of rice husk/polymer (lactic acid) (PLA) composites, and the relations between these properties and microscopic characteristics were investigated. The result showed that, with the increasing content of rice husk power, the maximum bearable tension and tensile strength increased; Water absorbability after 2 hours’ immersion hadn't significant change, but after 24 hours’ immersion, the water absorbing capacity had obvious addition. The study also showed that coupling agent could significantly reduce the water absorbability of composite materials; The use of scanning electron microscope (SEM) found that the interface became smoother, the adhesion between PLA and rice husk powder became closer when add the coupling agent to the rice husk powder, it also could well explain the differences between water absorbability and mechanical properties.

Accelerated Aging Tests of HTPB-Based Propellants

2018 ◽  
pp. 246-271
Author(s):  
Roberta Jachura Rocha
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Crosslink Density ◽  
Aging Process ◽  
Low Cost ◽  
Accelerated Aging ◽  
Solid Propellants ◽  
Launch Vehicles ◽  
Late Twentieth ◽  
Late Twentieth Century

In the late twentieth century, liquid and solid propulsion technologies have been integrated into hybrid engines currently apllied in propulsion launch vehicles and missiles. The reaction of polyol (HTPB) and diisocyanate (IPDI) provides the most versatile of the binders in the production of solid propellants due to its ability to withstand high loads combined with low cost and ease of processing. A propellant based on HTPB obtained in this study was submitted to natural and accelerated aging tests, seeking to evaluate the modifications of mechanical properties as tensile strength, elongation and hardness up to 360 days. The mechanism considered in the aging process is the increase of crosslink density by breaking the double bond contained in the HTPB molecule, which causes the instability of the propellant, increasing its handling risk. Samples of these propellants subjected to aging presented variations in their properties that match the values available in the literature.

Effect of polyamide 6 on the mechanical behavior of thermoplastic polyurethanes/polyamide 6 blends

2021 ◽  
pp. 095440542110406
Author(s):  
Nga Thi-Hong Pham
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Behavior ◽  
Thermoplastic Polyurethane ◽  
Polyamide 6 ◽  
Thermoplastic Polyurethanes ◽  
Microscope Images ◽  
Scanning Electron

Ductility and tensile strength are among the basic mechanical properties of polymers. Generally, it is difficult to enhance the ductility without significantly reducing the tensile strength. In this study, thermoplastic polyurethane (TPU) is mixed with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% polyamide 6 (PA6). The results show that the sample containing 100% TPU has the largest elongation of 690.5%. When PA6 is added, the elongation decreases gradually to 635.0%, 623.1%, 529.5%, 476.0%, 391.3%, and 242.8%, corresponding to 2.5%, 5%, 7.5%, 10%, 12.5%, and 100% PA6, respectively. The tensile strengths are 36.7, 33.8, 29.4, 26.5, 23.1, and 24.9 MPa, corresponding to 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PA6 samples, respectively. The tensile strength decreases gradually when the PA6 content is increased. Notably, the tensile strength of the 12.5% PA6 sample increases compared to the 10% PA6 sample. In addition, the hardness of the TPU/PA blend increases slightly as the PA6 ratio is increased. Finally, scanning electron microscope images demonstrate that PA6 particles act as particles dispersed or dissolved in TPU/PA blends.

Mechanical Properties and Microstructures of A356 Alloy Prepared by Casting Combined With Forging

2017 ◽  
Author(s):  
Zhenglong Liang ◽  
Qi Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
A356 Alloy ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Forging Process ◽  
Scanning Electron

A novel process which combines casting with forging during one process was proposed to improve mechanical properties and refine microstructure. The microstructure evolution of as-cast samples and forged samples were analyzed by optical microscope and scanning electron microscope (SEM). The tensile properties and micro-hardness were also measured. The results show that combination of casting and forging can improve microstructure and decrease porosity of casting samples, consequently contributing to a better fatigue performance. The ultimate tensile strength and elongation were increased after forging process, however, the yield strength and micro-hardness decreased.

Superior Mechanical Properties of Ultrasonically Recycled EPDM Rubber

2003 ◽  
Vol 76 (1) ◽  
pp. 253-270 ◽  
Author(s):  
Jushik Yun ◽  
A. I. Isayev
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Power Consumption ◽  
Crosslink Density ◽  
Dynamic Properties ◽  
Extensive Study ◽  
Processing Conditions ◽  
Elongation At Break ◽  
Epdm Rubber ◽  
Superior Mechanical Properties

Abstract This paper describes the results of an extensive study involving the continuous ultrasonic devulcanization of unfilled EPDM rubber. Die pressure and ultrasound power consumption were measured as a function of processing conditions. The mechanical properties of aged and fresh revulcanized EPDM rubber were measured. Gel fraction, crosslink density, and dynamic properties were also determined for the virgin vulcanizate, the ultrasonically devulcanized rubber, and the revulcanized rubber. Additionally, the cure behavior of virgin and devulcanized EPDM rubber was investigated. The tensile strength of revulcanized EPDM rubber was found to be much higher than that of the virgin vulcanizate with the elongation at break being practically intact. A mechanism explaining the increase in mechanical properties of revulcanized rubbers was proposed.

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