The aim of this study is presenting AFM analysis of surface roughness of Lithium disilicate glass... more The aim of this study is presenting AFM analysis of surface roughness of Lithium disilicate glass ceramic (IPS e.max CAD) under different finishing procedure (techniques): polishing, glazing and grinding. Lithium disilicate glass ceramics is all-ceramic dental system which is characterized by high aesthetic quality and it can be freely said that properties of material provide all prosthetic requirements: function, biocompatibility and aesthetic. Experimental tests of surface roughness were investigated on 4 samples with dimensions: 18 mm length, 14 mm width and 12 mm height. Contact surfaces of three samples were treated with different finishing procedure (polishing, glazing and grinding), and the contact surface of the raw material is investigated as a fourth sample. Experimental measurements were done using the Atomic Force Microscopy (AFM) of NT-MDT manufacturers, in the contact mode. All obtained results of different prepared samples are presented in the form of specific roughne...
1997 21st International Conference on Microelectronics. Proceedings, 1997
Free carriers in thin films was analysed using Green's function method in... more Free carriers in thin films was analysed using Green's function method including quantum size effect and effect of boundaries to Hamiltonian parameters. We calculate diagonal components of electron Green's functions, local densities of states, Fermi energy and spatial distribution of carriers concentration in thin film. The numerical calculations performed for GaAs films show that spatial distribution of free carriers may
This paper deals with the problem of defining the trajectory of a stiff burnishing tool that woul... more This paper deals with the problem of defining the trajectory of a stiff burnishing tool that would be optimal from the point of view of surface quality. The basic goal of this work is to gain an insight into the very process from the microscopic aspect, with the primary focus on material flow and roughness variations. Based on theoretical considerations, we planned an experiment with the aim to verify the initial hypotheses about the analysis of roughness change and a determination of the optimal depth of the workpiece penetration. Through matching and the superposition of surface profiles formed at various contact pressures, i.e., various burnishing forces and various penetration depths of the burnishing ball into the profile roughness, the phenomenon of roughness change was explained. Theoretical assumptions related to a determination of the optimum tool trajectory have largely been confirmed from the point of view of surface quality. The balls within the stiff tool system, which ...
The paper reviews contemporary research in the area of hybrid composites based on zinc and alumin... more The paper reviews contemporary research in the area of hybrid composites based on zinc and aluminium alloys reinforced with SiC and graphite particles. Metal matrix composites (MMCs) based on ZA matrix are being increasingly applied as light-weight and wear resistant materials. Aluminium matrix composites with multiple reinforcements (hybrid AMCs) are finding increased applications because of improved mechanical and tribological properties and hence are better substitutes for single reinforced composites. The results of research show that the hybrid composites possess higher hardness, higher tensile strength, better wear resistance and lower coefficient of friction when compared to pure alloys.
The structural, mechanical and tribological properties of ZA-27/SiC nanocomposites were investiga... more The structural, mechanical and tribological properties of ZA-27/SiC nanocomposites were investigated at micro/nanoscale. The nanocomposites with different volume fractions of nano-sized SiC particles were produced using the compocasting technique. The microstructure of nanocomposites was characterized with formation of SiC nano agglomerates, which were relatively uniformly distributed. The increase in SiC content contributed to the uniformity of their distribution. Also, the phenomenon of particle segregation in the form of particle-rich clusters, as well as particle-porosity clusters, was identified. The density level of composites decreased with the increase of the SiC content. The porosity followed a reverse trend. The tendency for formation of local particle-porosity clusters was the highest in ZA-27/1% SiC nanocomposite, causing the highest level of porosity. Increasing percentage of SiC content was followed by the increase in micro/nanohardness of the composites. The results o...
ABSTRACT The problem of measuring static friction at high temperatures and low contact pressures ... more ABSTRACT The problem of measuring static friction at high temperatures and low contact pressures is theoretically analyzed, as well as the instruments for the accurate determination of the coefficient of static friction at high temperatures for contact pairs made of steel and bronze. The results of experimental investigation show that at low contact pressure and temperature above 120°C coefficient of static friction dramatically increases. This increase in the coefficient of friction can be of great practical value with regard to the load capacity of contacts where external forces are balanced with friction forces.
Journal of the Balkan Tribological Association, 2012
ABSTRACT The influence of surface roughness on the coating adhesion of electrodeposited chrome co... more ABSTRACT The influence of surface roughness on the coating adhesion of electrodeposited chrome coatings with different roughnesses, has been evaluated using scratch testing technique. Coatings were deposited on the high alloyed tool steel. Photographs of the scratch grooves were recorded by the built-in optical microscope, at moments when critical loads had been reached. Crack pattern development was investigated. Results indicated that the increase of surface roughness lowers coating adhesion. Rough surfaces promote early coating failure, extensive spallation and early exposure of the substrate material.
The aim of this study is presenting AFM analysis of surface roughness of Lithium disilicate glass... more The aim of this study is presenting AFM analysis of surface roughness of Lithium disilicate glass ceramic (IPS e.max CAD) under different finishing procedure (techniques): polishing, glazing and grinding. Lithium disilicate glass ceramics is all-ceramic dental system which is characterized by high aesthetic quality and it can be freely said that properties of material provide all prosthetic requirements: function, biocompatibility and aesthetic. Experimental tests of surface roughness were investigated on 4 samples with dimensions: 18 mm length, 14 mm width and 12 mm height. Contact surfaces of three samples were treated with different finishing procedure (polishing, glazing and grinding), and the contact surface of the raw material is investigated as a fourth sample. Experimental measurements were done using the Atomic Force Microscopy (AFM) of NT-MDT manufacturers, in the contact mode. All obtained results of different prepared samples are presented in the form of specific roughne...
1997 21st International Conference on Microelectronics. Proceedings, 1997
Free carriers in thin films was analysed using Green's function method in... more Free carriers in thin films was analysed using Green's function method including quantum size effect and effect of boundaries to Hamiltonian parameters. We calculate diagonal components of electron Green's functions, local densities of states, Fermi energy and spatial distribution of carriers concentration in thin film. The numerical calculations performed for GaAs films show that spatial distribution of free carriers may
This paper deals with the problem of defining the trajectory of a stiff burnishing tool that woul... more This paper deals with the problem of defining the trajectory of a stiff burnishing tool that would be optimal from the point of view of surface quality. The basic goal of this work is to gain an insight into the very process from the microscopic aspect, with the primary focus on material flow and roughness variations. Based on theoretical considerations, we planned an experiment with the aim to verify the initial hypotheses about the analysis of roughness change and a determination of the optimal depth of the workpiece penetration. Through matching and the superposition of surface profiles formed at various contact pressures, i.e., various burnishing forces and various penetration depths of the burnishing ball into the profile roughness, the phenomenon of roughness change was explained. Theoretical assumptions related to a determination of the optimum tool trajectory have largely been confirmed from the point of view of surface quality. The balls within the stiff tool system, which ...
The paper reviews contemporary research in the area of hybrid composites based on zinc and alumin... more The paper reviews contemporary research in the area of hybrid composites based on zinc and aluminium alloys reinforced with SiC and graphite particles. Metal matrix composites (MMCs) based on ZA matrix are being increasingly applied as light-weight and wear resistant materials. Aluminium matrix composites with multiple reinforcements (hybrid AMCs) are finding increased applications because of improved mechanical and tribological properties and hence are better substitutes for single reinforced composites. The results of research show that the hybrid composites possess higher hardness, higher tensile strength, better wear resistance and lower coefficient of friction when compared to pure alloys.
The structural, mechanical and tribological properties of ZA-27/SiC nanocomposites were investiga... more The structural, mechanical and tribological properties of ZA-27/SiC nanocomposites were investigated at micro/nanoscale. The nanocomposites with different volume fractions of nano-sized SiC particles were produced using the compocasting technique. The microstructure of nanocomposites was characterized with formation of SiC nano agglomerates, which were relatively uniformly distributed. The increase in SiC content contributed to the uniformity of their distribution. Also, the phenomenon of particle segregation in the form of particle-rich clusters, as well as particle-porosity clusters, was identified. The density level of composites decreased with the increase of the SiC content. The porosity followed a reverse trend. The tendency for formation of local particle-porosity clusters was the highest in ZA-27/1% SiC nanocomposite, causing the highest level of porosity. Increasing percentage of SiC content was followed by the increase in micro/nanohardness of the composites. The results o...
ABSTRACT The problem of measuring static friction at high temperatures and low contact pressures ... more ABSTRACT The problem of measuring static friction at high temperatures and low contact pressures is theoretically analyzed, as well as the instruments for the accurate determination of the coefficient of static friction at high temperatures for contact pairs made of steel and bronze. The results of experimental investigation show that at low contact pressure and temperature above 120°C coefficient of static friction dramatically increases. This increase in the coefficient of friction can be of great practical value with regard to the load capacity of contacts where external forces are balanced with friction forces.
Journal of the Balkan Tribological Association, 2012
ABSTRACT The influence of surface roughness on the coating adhesion of electrodeposited chrome co... more ABSTRACT The influence of surface roughness on the coating adhesion of electrodeposited chrome coatings with different roughnesses, has been evaluated using scratch testing technique. Coatings were deposited on the high alloyed tool steel. Photographs of the scratch grooves were recorded by the built-in optical microscope, at moments when critical loads had been reached. Crack pattern development was investigated. Results indicated that the increase of surface roughness lowers coating adhesion. Rough surfaces promote early coating failure, extensive spallation and early exposure of the substrate material.
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Papers by Marko Pantic