Micro-Hardness of PA6 Influenced by Beta Irradiation

2015 ◽  
Vol 752-753 ◽  
pp. 322-325
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Crosslinking Agent ◽  
Polyamide 6 ◽  
Point Of View ◽  
Polymer Chains ◽  
Indentation Creep ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Micro Hardness ◽  
Depth Sensing

In this paper, the effect of the electron beam irradiation on the indentation hardness, indentation modulus and indentation creep have been studied by means of the Depth sensing indentation (DSI). Cross-linking is a process in which polymer chains are associated through chemical bonds. Radiation doses of 33, 66 and 99 kGy were used for unfilled polyamide 6 with the 7% crosslinking agent (triallyl isocyanurate). Beta irradiation of the examined thermoplastic caused the growth of values of material parameters as micro-hardness, indentation modulus or indentation creep etc. From this point of view, there may be new application in areas with mechanical properties higher than their original properties. This study compared the mechanical properties of irradiated and non-irradiated PA6.

scholarly journals LOCAL NANO-MECHANICAL PROPERTIES OF CROSS-LINKED POLYBUTYLENE

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.

Effect of Different Factors on Measured Values of Indentation Hardness of Interstitial Free Steel by Depth Sensing Indentation

2018 ◽  
Vol 784 ◽  
pp. 49-54
Author(s):  
Peter Burik ◽  
Ladislav Pešek ◽  
Zuzana Andršová ◽  
Pavel Kejzlar
Keyword(s):  
Mechanical Properties ◽  
Sample Surface ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Interstitial Free ◽  
Depth Sensing ◽  
Multiphase Materials ◽  
Material Characteristics ◽  
Straightforward Solution ◽  
Characterization Of Materials

Nanomechanical testing using depth sensing indentation (DSI) provides a straightforward solution for quantitatively characterizing each of phases in microstructure because it is very powerful technique for characterization of materials in small volumes. Measuring the local properties (indentation hardness HIT, indentation modulus EIT, indentation energy: total Wtotal, elastic Welast, plastic Wplast) of each microstructure component separately in multiphase materials gives information that is valuable for the development of new materials and for modelling. The mechanical properties of materials measured by DSI are affected by the experimental procedure, by the measurement conditions and factors which result from the material characteristics and device construction. We have to determine the effect of individual factors on the measurement in order to reach the repeatability and to allow the comparing the mechanical properties of the material. The aim of this investigation is to determine the measurement factors that affect indentation hardness of individual microstructural components and global mechanical properties of thin steel sheets. We investigated the factors which result from the material characteristics (crystallographic orientation of grain, grain boundary and anisotropy), preparation of the sample surface (roughness of sample surface) and method of measurement (pile-up, ISE).

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.

Irradiation of Polyamide Measured by Micro-Indentation Test

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%.

scholarly journals Mapping of the Micro-Mechanical Properties of Human Root Dentin by Means of Microindentation

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 505
Author(s):  
Michael Kucher ◽  
Martin Dannemann ◽  
Niels Modler ◽  
Martina Romy Bernhard ◽  
Christian Hannig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Indentation Creep ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Microstructural Alterations ◽  
Starting Point ◽  
Human Dentin ◽  
Root Dentin ◽  
Cervical Root ◽  
Martens Hardness

The extensive knowledge of root dentin’s mechanical properties is necessary for the prediction of microstructural alterations and the teeth’s deformations as well as their fracture behavior. Standardized microindentation tests were applied to apical, medial, and cervical root sections of a mandibular human first molar to determine the spatial distribution of the hard tissue’s properties (indentation modulus, indentation hardness, Martens hardness, indentation creep). Using an indentation mapping approach, the inhomogeneity of mechanical properties in longitudinal as well as in transversal directions were measured. As a result, the tooth showed strongly inhomogeneous material properties, which depended on the longitudinal and transversal positions. In the transversal cutting planes of the cervical, medial, apical sections, the properties showed a comparable distribution. A statistical evaluation revealed an indentation modulus between 12.2 GPa and 17.8 GPa, indentation hardness between 0.4 GPa and 0.64 GPa and an indentation creep between 8.6% and 10.7%. The established standardized method is a starting point for further investigations concerning the intensive description of the inhomogeneous mechanical properties of human dentin and other types of dentin.

Investigation of Mechanical Properties of Mono- and Multi-layer Alumina and Ceria Films Using Finite Element Modeling and Nanoindentation Experiments

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Sabina Cherneva ◽  
Desislava Guergova ◽  
Roumen Iankov ◽  
Dimitar Stoychev
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Single Layer ◽  
Point Of View ◽  
Indentation Hardness ◽  
Indentation Modulus ◽  
Al2o3 Layer ◽  
Plastic Properties ◽  
Aluminum Ions ◽  
Ceo2 Film

Important from exploitation point of view mechanical properties of single-layer, double-layer, and mixed alumina and ceria films and their stainless steel (SS) substrate were investigated by means of nanoindentation experiments. As a result, we obtained the experimental load–displacement curves and calculated the indentation hardness (HIT) and indentation modulus (EIT), by means of Oliver and Pharr approximation method. Numerical simulations of the process of nanoindentation by means of finite element method were performed as well, in order to obtain more information about the plastic properties of the investigated films. The obtained results show that the mixed Al2O3+Ce2O3 film, obtained at dominant concentration of cerium ions in the working electrolyte, has the highest indentation hardness and modulus, followed by the single Ce2O3-CeO2 film, the mixed Al2O3+Ce2O3 film, obtained at dominant concentration of aluminum ions in the working electrolyte, the double Ce2O3-CeO2/Al2O3 layer, and single Al2O3 layer.

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 Effect of Cross-Linking on Nano-Mechanical Properties of Polyamide

2016 ◽  
Vol 699 ◽  
pp. 37-42 ◽  
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Material Properties ◽  
Basic Material ◽  
Nanoindentation Test ◽  
Cross Linking ◽  
Indentation Hardness ◽  
Depth Sensing ◽  
Nanomechanical Properties ◽  
Radiation Crosslinking

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.

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.

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