Micro-Indentation Test of Cross-Linking Polyethylene

Radiation crosslinking of polyamidu 6 (PA 6) is a well-recognized modification of improving basic material characteristics. 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. This research paper deals with the possible utilization of irradiated PA6. The material already contained a special cross-linking agent TAIC (5 volume %), which should enable subsequent cross-linking by ionizing β – radiation (15, 30 and 45 kGy). The effect of the irradiation on mechanical behavior of the tested PA 6 was investigated. Material properties created by β – radiation are measured by nanoindentation test using the DSI method (Depth Sensing Indentation). Hardness increased with increasing dose of irradiation at everything samples; however results of nanoindentation test shows increasing in nanomechanical properties of surface layer. The highest values of nanomechanical properties were reached radiation dose of 45 kGy, when the nanomechanical values increased by about 95%. These results indicate advantage cross-linking of the improved mechanical properties.

Download Full-text

Irradiation of Polyamide Measured by Micro-Indentation Test

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.1179 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 1179-1182

Author(s):

Martin Ovsik ◽

David Manas ◽

Miroslav Manas ◽

Michal Stanek ◽

Adam Skrobak ◽

...

Keyword(s):

Mechanical Properties ◽

Surface Layer ◽

Material Properties ◽

Indentation Test ◽

Polymer Chains ◽

Cross Linking ◽

Indentation Hardness ◽

Chemical Bonds ◽

Depth Sensing ◽

Micro Indentation

Cross-linking is a process in which polymer chains are associated through chemical bonds. This research paper deals with the possible utilization of irradiated polyamide. Influence of the intensity of irradiation on micro-indentation hardness was investigated. Material properties created by β – radiation are measured by micro-indentation test using the DSI method (Depth Sensing Indentation). Hardness increased with increasing dose of irradiation at everything samples; however results of micro-indentation test shows increasing in micro-mechanical properties of surface layer. The highest values of micro-mechanical properties were reached radiation dose of 99 kGy, when the micro-mechanical values increased by about 18%.

Download Full-text

Improving Surface Properties of Linear Polyethylene by Radiation Measured by Ultra-Nano Indentation Test

Materials Science Forum ◽

10.4028/www.scientific.net/msf.952.172 ◽

2019 ◽

Vol 952 ◽

pp. 172-179

Author(s):

Martin Ovsik ◽

Michal Stanek ◽

Adam Dockal ◽

Martin Reznicek ◽

Lenka Hylova

Keyword(s):

Mechanical Properties ◽

Surface Properties ◽

Three Dimensional ◽

Indentation Test ◽

Optimal Dose ◽

Indentation Hardness ◽

Indentation Modulus ◽

Deformation Work ◽

Correct Function ◽

Economical Aspect

Surface properties are important aspect for correct function of construction (technical) parts. By improving mechanical properties of surface, an increase of abrasion resistance and wear resistance is reached. Longevity and economical aspect have an important role in final useful properties of product. Measurement of surface properties was done by ultra-nanoindentation technique (UNHT3), this is the best tool available right now, this technique is based on instrumented testing. Surface properties were modified by ionized radiation, that caused the creation of crosslinked structure in polyethylene. During radiation a three dimensional network is created, that improves final properties of product such as: hardness, elasticity modulus, thermal stability, etc. During ionized radiation there are two actions that take place at the same time, crosslinking and degradation. Goal of this paper is to consider how radiation intensity affects surface properties (indentation hardness, indentation modulus, deformation work, etc.) Another goal of this paper is to find out the optimal dose of radiation, that will cause more three dimensional crosslinking and less degradation as degradation causes decrease in mechanical properties.

Download Full-text

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

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.368.138 ◽

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.

Download Full-text

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.699.43 ◽

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.

Download Full-text

Surface Properties of Crosslinking Polyamide Measured by Micro-Indentation Test

Materials Science Forum ◽

10.4028/www.scientific.net/msf.919.111 ◽

2018 ◽

Vol 919 ◽

pp. 111-119

Author(s):

Martin Ovsik ◽

Michal Stanek ◽

Vojtech Senkerik

Keyword(s):

Mechanical Properties ◽

Surface Layer ◽

Surface Properties ◽

Electron Beam Irradiation ◽

Indentation Test ◽

Polymer Chains ◽

Beta Radiation ◽

Cross Linking ◽

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 behavior. This paper studies the effect of different doses of ionizing beta radiation on the micro-mechanical properties of commercially available polyamide. The measured results indicate, that electron beam irradiation is very effective tool for improvement of surface properties of PA6. In terms of micro-mechanical properties, the values of micro-hardness of surface layer increased by 24% at radiation dose of 132 kGy, stiffness of surface micro layer by 26% (132 kGy) as a result of different loads (0.5N and 2N). Improvement of micro-mechanical properties of radiated polyamide has a great significance also for industry. The modified polyamide shifts to the group of materials that have considerably better properties. Its micro-mechanical properties make polyamide ideal for a wide application in areas where higher resistance to wear, creep are required. Commonly manufactured PA6 can hardly fulfil these criteria.

Download Full-text

Nano-indentation test of electron beam irradiated polyamide 11

MATEC Web of Conferences ◽

10.1051/matecconf/201821002037 ◽

2018 ◽

Vol 210 ◽

pp. 02037

Author(s):

Martin Ovsik ◽

Lenka Hylova ◽

Ivan Hudec ◽

Adam Dockal

Keyword(s):

Mechanical Properties ◽

Electron Beam ◽

Indentation Test ◽

Polymeric Materials ◽

Beta Radiation ◽

High Tech ◽

Indentation Hardness ◽

Indentation Modulus ◽

Beam Radiation ◽

Polyamide 11

This article deals with the influence of electron beam radiation on nano-mechanical properties and the structure of polyamide 11. Crosslinking of polymers is a process, during which macromolecular chains start to connect to each other and the spatial network creates in the structure. During the action of the ionizing radiation two actions can occur: crosslinking and scission of macromolecules – degradation. Both these processes run parallel. Using the crosslinking technology the standard and construction polymer can obtain the more “expensive” high-tech polymeric materials properties and thus replace these materials in many applications. Tested material was irradiated by different doses of beta radiation (33, 66 and 99 kGy). The nano-mechanical properties were measured using DSI method, which fluently records the change of the indentation in time. From this dependence it is possible to determine nano-mechanical properties such as indentation hardness, indentation modulus etc. During results consideration it is obvious that irradiation acts on each polymer differently, but always when the optimal dose was found, nano-mechanical properties increased up to 34 %. The changes of nano-mechanical properties were confirmed by structural measurement when the change of hardness and modulus corresponded to gel content.

Download Full-text

Micro-Indentation Test and Morphology of Electron Beam Irradiated HDPE

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.662.189 ◽

2015 ◽

Vol 662 ◽

pp. 189-192

Author(s):

Martin Ovsik ◽

Petr Kratky ◽

David Manas ◽

Miroslav Manas ◽

Michal Stanek ◽

...

Keyword(s):

Mechanical Properties ◽

Indentation Test ◽

Polymer Chains ◽

Cross Linking ◽

Thermal Treatments ◽

X Ray Diffraction ◽

Irradiation Dosage ◽

The Cross ◽

Micro Indentation ◽

Different Doses

Cross-linking is a process in which polymer chains are associated through chemical bonds. The cross-linking level can be adjusted by the irradiation dosage and often by means of a cross-linking booster. The polymer additional cross-linking influences the surface nanoand micro layers in the way comparable to metals during the thermal and chemical-thermal treatments. The aim of this paper is to study the effect of ionizing radiation with different doses (33, 66 and 99 kGy), on micro-mechanical properties of polyethylene (HDPE) and compare these results with those of non-irradiated samples. Influence of the cross-linking by β – radiation of the tested HDPE on micro-indentation test and morphology was investigated. Micro-mechanical properties increased with increasing value of the dose of irradiation material. The changes were examined and confirmed by X-ray diffraction.

Download Full-text

LOCAL NANO-MECHANICAL PROPERTIES OF CROSS-LINKED POLYBUTYLENE

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2020.27.0112 ◽

2020 ◽

Vol 27 ◽

pp. 112-115

Author(s):

Martin Ovsík ◽

Michal Staněk ◽

Adam Dočkal ◽

Petr Fluxa

Keyword(s):

Mechanical Properties ◽

High Performance ◽

Polymer Chains ◽

Cross Linking ◽

Indentation Hardness ◽

Indentation Modulus ◽

Depth Sensing ◽

Polybutylene Terephthalate ◽

3D Network ◽

Irradiation Dosage

Cross-linking is a process in which polymer chains are associated through chemical bonds. The cross-linking level can be adjusted by the irradiation dosage and often by means of a cross-linking booster. The polymer additional cross-linking influences the surface nano and micro layers in the way comparable to metals during the thermal and chemical-thermal treatments. Polybutylene terephthalate (PBT) can be found in a group of structural polymers, which are often used in industry, especially in automotive. Applying the technology of electron radiation induces a creation of 3D network structure, which improves the local mechanical properties. These were later measured by a depth sensing indentation (DSI) test. This state of the art method is based on immediate detection of indentation depth in relation to applied force. The creation of 3D network caused an increase in nano-mechanical properties values, such as indentation hardness and indentation modulus, in comparison to the virgin material. The indentation hardness rose by 80%, while the indentation modulus elevated by 62%. The selected structural materials, e.g. PBT, were modified by the electron irradiation in a positive way and as such could be moved to a group of high performance materials.

Download Full-text

Indentation Measurement of CuZnAl Dual Phase Shape Memory Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.784.38 ◽

2018 ◽

Vol 784 ◽

pp. 38-43

Author(s):

Marek Vojtko ◽

Ján Balko ◽

Martin Fides ◽

Liudmila Vojtkova

Keyword(s):

Mechanical Properties ◽

Shape Memory ◽

Indentation Test ◽

Phase Region ◽

Indentation Hardness ◽

Indentation Modulus ◽

Dual Phase ◽

Quenching Temperature ◽

Β Phase ◽

Α Phase

The aim of this work is indentation study of local mechanical properties of Cu-22Zn-4.6Al alloy, which has significant shape memory effect after quenching from dual α + β phase region. The study was carried out on the samples with thermoelastic and non-thermoelastic martensite in the structure, which were obtained by quenching from various temperatures. A different behavior concerning mechanical properties measurements of α phase and β phase transformed to martensite after quenching from various temperatures was found out. It was observed almost no change of mechanical properties of α phase, whereas indentation hardness HIT and indentation modulus EIT raised with increasing quenching temperature. Also some serious differences were observed at indentation test of thermoelastic and non-thermoelastic martensite.

Download Full-text