scholarly journals Influence of electron irradiation on mechanical properties of epoxy polymers

2020 ◽  
Vol 99 (3) ◽  
pp. 80-85
Author(s):  
Yu.A. Udovytska ◽  

The effect of different absorbed doses of electron irradiation with the energy of 12 MeV and heat treatment on the mechanical properties of ED-20 epoxy-dianic resin with hardener PEPA (11, 12 and 13 parts by weight per 100 parts by weight of epoxy resin) was investigated. Heat treatment of irradiated epoxy resin samples was performed in two modes: before or after electron irradiation. It is shown that the optimal choice of the content of hardener PEPA and using electron irradiation with the energy of 12 MeV in the integrated combination with heat treatment allow significantly improve the mechanical properties of epoxy-dianic resin. It was established that for the content of the hardener 12 parts by weight and absorbed doses of 10–20 kGy, the boundary of strength increases in 3 times, and additional heat treatment both before and after irradiation reduces this figure through the thermal destruction. Only for the content of hardener 11 and 13 parts by weight and these absorbed doses heat treatment of irradiated samples of epoxy resin leads to an increase in the boundary of strength. In doing so, the hardness increases regardless of the content of hardener for the absorbed doses greater than 50 kGy.

2020 ◽  
Vol 1 (23) ◽  
pp. 81-89
Author(s):  
Yuliia Udovytska ◽  
Sergiy Luniov ◽  
Vitalii Kashytskyi ◽  
Volodymyr Maslyuk ◽  
Ivan Megela

The influence of electron irradiation fluxes with energy of 12 MeV and heat treatment on the electrical properties of epoxypolymers with PEPA content of 11, 12 and 13 wt.h. per 100 wt. including epoxy resin. It is show that the electrical conductivity of epoxypolymer increases with electron irradiation fluxes greater than 10 kGy. It  found that extra heat treatment of irradiated samples with a hardener content of 12 wt. h. hours leads to an increase in their electrical conductivity. The nature of the obtained dependences of electrical conductivity is determine by the processes of cross-linking, radiation, thermal destruction and mass fraction of the hardener. Radiation-stimulated increase in the conductivity of epoxypolymers can be use to create conductive protective coatings and sensor electronics elements


2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.


2020 ◽  
Vol 321 ◽  
pp. 08003
Author(s):  
Yujun Du ◽  
Xianghong Liu ◽  
Jinshan Li ◽  
Wenzhong Luo ◽  
Yongsheng He ◽  
...  

Small button ingots of Ti2AlNb alloys with different contents of Mo, V and Zr were melted by vacuum non-consumable arc furnace. Due to the rapid cooling rate during melting process, only β grains without precipitation were observed in most of the button ingots and no regular phenomenon was found. However, when the samples were heated to β phase region and then furnace cooled to room temperate, different morphologies and quantities of primary α phase and second O phase formed from the β grains of different samples. It is suggested that the morphology of α phase was changed from lamellar to quadrilateral with increasing V and the lath O increased with increasing Zr. Besides, the residual β/B2 phase increased with increasing Mo and V. The EDS results showed that Al and Zr were enriched in α phase whereas Nb, Mo and V were enriched in β/B2 phase. The micro-hardness of these samples before and after heat treatment was detected and the micro-hardness increased with increasing Zr and decreasing Mo and V.


2018 ◽  
Vol 27 (47) ◽  
pp. 101
Author(s):  
Sandra Arias ◽  
Maryory Gómez ◽  
Esteban Correa ◽  
Félix Echeverría-Echeverría ◽  
Juan Guillermo Castaño

Nickel-Boron autocatalytic coatings are widely used in several industries to improve mechanical properties of materials such as hardness and wear resistance. Tribological properties were evaluated in Ni-B autocatalytic coatings deposited on AISI/SAE 1018 carbon steel before and after a heat treatment at 450 °C for one hour. Tribological tests were carried out by dry sliding, using a load of 5 N and a sliding speed of 0.012 m/s, in a homemade ball-on-disk tribometer, which followed ASTM G99 standard. According to the tribological evaluation, the heat treatments applied to Ni-B coatings improved their tribological performance. This research corroborates that by applying an adequate heat treatment, hardness and wear resistance of Ni-B coatings can be improved significantly.


2019 ◽  
Vol 944 ◽  
pp. 64-72
Author(s):  
Qing Feng Yang ◽  
Cun Juan Xia ◽  
Ya Qi Deng

Bulky sample was made by using TIG wire and arc additive manufacturing (WAAM) technology, in which Ф1.6 mm filler wire of in-situ TiB2/Al-Si composites was selected as deposition metal, following by T6 heat treatment. The microstructure and mechanical properties of the bulky sample before and after heat treatment were analyzed. Experimental results showed that the texture of the original samples parallel to the weld direction and perpendicular to the weld direction was similar consisting of columnar dendrites and equiaxed crystals. After T6 heat treatment, the hardness of the sample was increased to 115.85 HV from 62.83 HV, the yield strength of the sample was 273.33 MPa, the average tensile strength was 347.33 MPa, and the average elongation after fracture was 7.96%. Although pore defects existed in the fracture, yet the fracture of the sample was ductile fracture.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 863 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang ◽  
Jing Wang ◽  
Xuehua Wang

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.


2013 ◽  
Vol 747-748 ◽  
pp. 111-114
Author(s):  
Lin Song ◽  
Xiang Jun Xu ◽  
Jun Pin Lin ◽  
Lai Qi Zhang

Effects of annealing treatment on microstructure and the compressive properties of hot-worked Ti-45Al-8Nb-(W, B, Y) alloy were investigated. Microstructure of the extrusion plus multi-step forging pancake before and after heat treatment was analyzed by SEM and TEM, respectively. The annealing was conducted by holding samples at 1100°C for 2hrs, and followed by air cooling and furnace cooling. The mechanical properties were measured by Instron test machine. The microstructure evolution during compressive deformation was analyzed by TEM. The results showed that after the annealing the microstructure change could not be observed under SEM but can be observed under TEM. Many dislocation clusters were removed by heat treatment. The heat treated samples had similar compression behaviors with the pancake. TEM investigation showed that the numerous twin intersections occured in γ matrix during compression. The twin spaces tended to decrease as the deformation and the intersection increasing.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1269-1275
Author(s):  
Anatoly A. Popovich ◽  
Vadim Sh. Sufiiarov ◽  
Igor A. Polozov ◽  
Evgenii V. Borisov ◽  
Maxim Y. Maximov

The article presents the results of selective laser melting of Ti-6Al-4V alloy. It was studied phase composition and microstructure of the initial powder material, the specimens manufactured by Selective Laser Melting and also the specimens after heat treatment. The effect of heat treatment on microstructure and mechanical properties of the specimens was shown. It was studied the mechanical behavior of the manufactured specimens before and after heat treatment at room and elevated temperatures as well. After heat treatment tests showed that the specimens have decent mechanical properties both at room and elevated temperatures.


Author(s):  
Amit Kumar

In this work we have analyzed the effect heat treatment on properties of spring shape steel specimens under various heat treatment processes. Specimen was subjected to heat treatment in electric muffle furnace. Heat treatment temperature, soaking time and cooling rate were selected as per phase diagram of specimen material. Specimen was tested for mechanical properties before and after heat treatment. Two processes annealing and normalizing compared with respect to their effect on properties of spring shape specimens in reference with standard data for steel used.


2021 ◽  
Vol 233 ◽  
pp. 01097
Author(s):  
Yongqiang Zhong

By referring to the domestic and foreign researches on color anti-skid pavement, the composition of epoxy resin coating material for color antiskid pavement is designed. The purpose of the experiment is to analyze the effect of nano-modified epoxy resin coating by adding 2.5% nano-organic montmorillonite modifier to the existing color anti-skid pavement surface material. Test and compare the change of mechanical properties of nano-modified epoxy resin coating binder before and after nano-modified. Then the effect of nano-modification is analyzed.


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