Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

The Behaviour of Cross-Linking Filled PP to Micro-Indentation Test

2016 ◽  
Vol 368 ◽  
pp. 138-141
Author(s):  
Martin Ovsík ◽  
Vojtech Šenkeřík ◽  
David Manas ◽  
Miroslav Maňas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Indentation Test ◽  
Polymer Chains ◽  
Beta Radiation ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Micro Indentation ◽  
Different Doses

Cross-linking is a process in which polymer chains are associated through chemical bonds. Radiation, which penetrated through specimens and reacted with the cross-linking agent, gradually formed cross-linking (3D net), first in the surface layer and then in the total volume, which resulted in considerable changes in specimen behaviour. The aim of the experiments was to study the influence of different doses of Beta radiation to the structure and micro-mechanical properties of polypropylene filled by 30% glass fiber (PP+GF). Hard surface layers of PP+GF can be formed by radiation cross-linking by β – radiation with doses of 33, 66 and 99 kGy. Material properties created by β – radiation are measured by micro-indentation test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the PP+GF tested. Micro-mechanical properties increased with increasing value of the dose of irradiation material (increase about 49%). The changes were examined and confirmed by X-ray diffraction.

Micro-Hardness Test of Cross-Linking LLDPE

2017 ◽  
Vol 1142 ◽  
pp. 134-137
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Vaclav Janostik
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Hardness Test ◽  
Cross Linking ◽  
Radiation Doses ◽  
Micro Hardness ◽  
Depth Sensing ◽  
Linear Polyethylene ◽  
Hardness Values ◽  
Different Doses

The presented article deals with the research of micro-mechanical properties in the surface layer of modified linear polyethylene (LLDPE). These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation (0, 66, 132 and 198 kGy ). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LLDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 132 kGy, when the micro-hardness values increased by about 29%. These results indicate advantage crosslinking of the improved mechanical properties.

scholarly journals Effect of Beta Low Irradiation Doses on the Filled PA66 Measured by Micro-Indentation Test

2014 ◽  
Vol 1025-1026 ◽  
pp. 415-418
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Indentation Test ◽  
Radiation Doses ◽  
Micro Hardness ◽  
Polyamide 66 ◽  
Depth Sensing ◽  
Micro Indentation ◽  
Hardness Values ◽  
Different Doses

The presented article deals with the research of micro-mechanical properties in the surface layer of modified Polyamide 66 filled by 30% of glass fibers. These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. Radiation doses used were 0, 15, 30 and 45 kGy for filled Polyamide 66 with the 6% cross-linking agent (triallyl isocyanurate). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the polyamide 66 tested. The highest values of micro-mechanical properties were reached at radiation dose of 30 kGy, when the micro-hardness values increased by about 64%. The aim of the article is to find out the influence of the radiation on the micro-hardness of the modified glass fiber-filled Polyamide 66 (PA66).

Improvement of PA6 Mechanical Properties by Radiation Cross-Linking

2015 ◽  
Vol 1120-1121 ◽  
pp. 1163-1166 ◽  
Author(s):  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Ovsik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Polymer Material ◽  
Polyamide 6 ◽  
Polymer Materials ◽  
Cross Linking ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hard Surface ◽  
End Use

Influence of mechanical properties of the hard surface layer of modified polyamide 6 is studied. Mechanical properties are acquired by nanohardness test with using the DSI method (Depth Sensing Indentation). Hard surface layers are created by radiation cross-linking technology. This technology allows polymer materials modification followed by the change of their end-use properties. The surface layer of polymer material is modified by ionizing β - radiation. When the polymer material is exposed to the β radiation, it is possible to observe changes of the surface layer at applied load. Radiation cross-linking usually improves strength, reduces creep, contributes to chemical resistance improvement, and in many cases improves tribological properties.

Surface Layer Micro-Hardness of Modified LDPE by Radiation Cross-Linking after Temperature Load

2015 ◽  
Vol 662 ◽  
pp. 177-180 ◽  
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Martin Ovsik ◽  
Martina Kaszonyiová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Cross Linking ◽  
Indentation Hardness ◽  
Micro Hardness ◽  
Depth Sensing ◽  
Indentation Method ◽  
Temperature Load ◽  
Irradiation Process ◽  
Different Doses

The presented article deals with the research of surface layer ́s micro-mechanical properties of modified LDPE by radiation cross-linking after temperature load. These micro-mechanical properties were measured by the DSI (Depth Sensing Indentation) method on samples which were non-irradiated and irradiated by different doses of the β – radiation and then were temperature loaded. The purpose of the article is to consider to what extent the irradiation process influences the resulting micro-mechanical properties measured by the DSI method. The LDPE tested showed significant changes of indentation hardness and modulus after temperature load.

The Behaviour of Cross-Linking Filled PA66 by Micro-Indentation Test

2016 ◽  
Vol 699 ◽  
pp. 43-48
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Vojtech Senkerik
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Glass Fiber ◽  
Indentation Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Polyamide 66 ◽  
Depth Sensing

The process of radiation crosslinking helps to improve some mechanical properties of polymer materials. Micro-mechanical changes in the surface layer of glass-fiber filled PA 66 modified by beta radiation were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. The specimens were prepared by injection technology and subjected to radiation doses of 0, 33, 66 nad 99 kGy. The change of micro-mechanical properties is greatly manifested mainly in the surface layer of the modified polypropylene where a significant growth of micro-hardness values can be observed. Indentation modulus increased from 1.8 to 3.0 GPa (increasing about 66%) and indentation hardness increased from 87 to 157 MPa (increasing about 80%). This research paper studies the influence of the dose of irradiation on the micro-mechanical properties of semi-crystalline polyamide 66 filled by 30% glass fiber at room temperature. The study is carried out due to the ever-growing employment of this type of polymer.

scholarly journals Nano-Mechanical Properties of Surface Layers of Polyethylene Modified by Irradiation

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 929 ◽  
Author(s):  
Martin Ovsik ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Adam Dockal ◽  
Ales Mizera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Test Sample ◽  
High Energy ◽  
Beta Radiation ◽  
Depth Sensing ◽  
Surface Layers ◽  
Structural Modifications ◽  
Crosslinking Process ◽  
High Energy Electrons ◽  
Wide Range

This study’s goal was to describe the influence of a wide range of ionizing beta radiation upon the changes in surface layer mechanical properties and structural modifications of selected types of polymer. Radiation crosslinking is a process whereby the impingement of high-energy electrons adjusts test sample structures, thus enhancing the useful properties of the material, e.g., hardness, wear-resistance, and creep, in order that they may function properly during their technical use. The selected polymers tested were polyolefin polymers like polyethylene (Low-density polyethylene LDPE, High-density polyethylene HDPE). These samples underwent exposure to electron radiation of differing dosages (33, 66, 99, 132, 165, and 198 kGy). After the crosslinking process, the samples underwent testing of the nano-mechanical properties of their surface layers. This was done by means of a state-of-the-art indentation technique, i.e., depth-sensing indentation (DSI), which detects the immediate change in the indentation depth associated with the applied force. Indeed, the results indicated that the optimal radiation dosage increased the mechanical properties by up to 57%; however, the beneficial levels of radiation varied with each material. Furthermore, these modifications faced examination from the structural perspective. For this purpose, a gel test, Raman spectroscopy, and crystalline portion determination by X-ray all confirmed the assumed trends.

scholarly journals Experimental Evaluation of Mechanical Properties of Friction Welded Dissimilar Steels under Varying Axial Pressures

2016 ◽  
Vol 66 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Amit Handa ◽  
Vikas Chawla
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Failure Analysis ◽  
Friction Welding ◽  
Experimental Evaluation ◽  
Micro Hardness ◽  
Aisi 304 ◽  
Torsional Strength ◽  
Hardness Values

AbstractThe present study emphasizes on joints two industrially important materials AISI 304 with AISI 1021steels, produced by friction welding have been investigated. Samples were welded under different axial pressures ranging from 75MPa to 135MPa, at constant speed of 920rpm. The tensile strength, torsional strength, impact strength and micro hardness values of the weldments were determined and evaluated. Simultaneously the fractrography of the tensile tested specimens were carried out, so as to understand the failure analysis. It was observed that improved mechanical properties were noticed at higher axial pressures. Ductile failures of weldments were also observed at 120MPa and 135MPa axial pressures during fractography analysis.

scholarly journals Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: I. specific features of the test method procedure

2004 ◽  
Vol 36 (1) ◽  
pp. 27-41 ◽  
Author(s):  
A.V. Byakova ◽  
Yu.V. Milman ◽  
A.A. Vlasov
Keyword(s):  
Mechanical Properties ◽  
Indentation Load ◽  
Test Method ◽  
Simplified Model ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Modified Model ◽  
Plasticity Characteristic ◽  
Measurement Results ◽  
Hardness Values

Specific features of the test method procedure capable for determining the plasticity characteristic dH by indentation of inhomogeneous coatings affected by residual stress was clarified. When the value of the plasticity characteristic for coating was found to be as great as dH > 0.5 a simplified model was found to be reasonably adequate, while a modified model assumed compressibility of the deformation core beneath indentation. The advantage of the modified approach compared to the simplified one was grounded experimentally only if the elastic deformation for coating becomes greater than ?e ? 3.5%, resulting in the decrease of plasticity characteristic dH < 0.5. To overcome non accuracy caused by the effect of the scale factor on measurement results a comparison of different coatings was suggested using stabilized values of the plasticity characteristic dH determined under loads higher than critical, P ? Pc, ensuring week dependence of micro hardness values on the indentation load.

Influence of Aging Treatments on the Structural and Mechanical Properties of AGS Alloy Wire Cold Drawn

2018 ◽  
Vol 18 ◽  
pp. 73-78
Author(s):  
Mokhtar Bayarassou ◽  
Mosbah Zidani ◽  
Hichem Farh
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Electron Microscope ◽  
Artificial Ageing ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Alloy Wire ◽  
X Ray ◽  
Plastic Deformation Rate ◽  
Scanning Electron

The scope of this work is to study of microstructural changes and mechanical properties during natural and artificial ageing treatment of AGS Alloy wire cold drawn with different deformation at ENICAB in Biskra. And as well to know the phase formation during different deformation of aluminum alloys wires. as well as the combined influence of the plastic deformation rate and the aging temperature. Wire section reduction shows a change in microstructure and texture. The methods of characterization used in this work are: scanning electron microscope and X-ray diffraction, micro hardness (Hv).

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