Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 9

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Influence of CaO on the Nanohardness Behaviour of AZ63 Magnesium Alloys Produced by Mechanical Alloying Method

100%
Boztas M., Ozarslan S., Sahin O.
Acta Physica Polonica A
|
2016
|
vol. 130
|
issue 1
357-361
EN
In this study we aimed to produce AZ63 magnesium alloys containing different amounts of CaO, to investigate the nanohardness behaviour of the resulting alloys. These alloys were produced by mechanical alloying under argon atmosphere. Magnesium based alloys with the initial CaO content of 0.1%, 0.3%, and 0.5% were produced by high-energy ball milling, followed by process that involved cold pressing and sintering. These alloys were characterized using scanning electron microscopy, scanning probe microscopy, X-ray diffraction, and nanoindentation methods. Unloading segments of nanoindentation curves were analyzed using Oliver-Pharr method. Experimental results show that measured nanohardness exhibits a peak load dependence. As a result, in these alloys the microstructure and nanohardness depend on the content of CaO.
2
Content available remote

Mechanical Properties of Boronized AISI 316, AISI 1040, AISI 1045 and AISI 4140 Steels

100%
Calik A., Sahin O., Ucar N.
Acta Physica Polonica A
|
2009
|
vol. 115
|
issue 3
694-698
EN
In this study, some mechanical properties of borided and unborided four steels were investigated. Boronizing of steels was performed by powder pack method at 1210 K for 4 h. The hardness of borides, boride layer thickness and room temperature tensile properties were measured and it was observed that hardness and tensile properties strongly depend on chemical composition of steels. In addition, the effect of a notch on impact behavior was examined by conducting the Charpy tests on borided and unborided steels. The greatest notch toughness was found for a steel AISI 316 with a microstructure consisting of different C, Ni and Cr chemical composition compared to AISI 1040, 1045 and 4140 steels.
3
Content available remote

Influence of Pd Addition of CoCrMo Biomedical Alloys on the Microhardness Behaviour

100%
Sahin O., Uzunoglu S., Sahin E.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 2B
B-145-B-148
EN
CoCrMo alloys are often used as the material for metal artificial joint because of their high corrosion resistance and mechanical properties. In this study CoCrMo alloys having different palladium amount of produced by investment casting method. Scanning electron microscopy, X-ray diffraction method and indentation tests were used to examine the mechanical properties of the alloys. Indentation experiments were carried out using Vickers indenter that the loads range from 0.245 to 9.8 N. The alloys exhibit significant load-dependence (i.e., indentation size effect). Meyer's law, proportional specimen resistance model, and Hays-Kendall model were used to analyze the load dependence of the hardness. As a results for load-independent determination of the CoCrMo alloys, the Hays-Kendall model is found to be more effective than the proportional specimen resistance model and microhardness values decreases with increase of the Pd content.
4
Content available remote

Mechanical Characterization of CoCrMo Alloys Consisting of Different Palladium Ratios Produced by Investment Casting Method

100%
Sahin O., Uzunoglu S., Sahin E.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 2B
B-149-B-151
EN
CoCrMo alloys are one of the most commonly used materials for hip arthroplasty, knee and dental because of its mechanical properties, corrosion resistance, wear resistance and biocompatibility. In this study, CoCrMo alloys consisting of 1.68 to 4.33%Pd are produced by investment casting process under argon atmosphere. The microstructures and mechanical properties of CoCrMo alloy were studied using X-ray diffraction, optical microscopy, scanning electron microscopy, Knoop indentation hardness tests, focusing on the influences on the different palladium additives. The measured microhardness values of CoCrMo alloys having different palladium ratio are seen to be load-dependent. The observed load dependence was rationalized using the Hays-Kendall model and it was found that the resultant load-independent hardness decreases with increase of palladium ratios. As a results, microhardness decreases with increase of palladium amount.
5
Content available remote

Influence of Rare Earth Element on the Mechanical Properties of ZE41 Magnesium Alloys Produced by Mechanical Alloying

100%
Sahin O., Haluk Ertsak F., Oztekin K., Ozarslan S.
Acta Physica Polonica A
|
2016
|
vol. 130
|
issue 1
289-292
EN
In this work, we have intended to synthesize ZE41 Magnesium alloys having varying content of Ce of 0.3, 0.6 and 0.9 wt.% and to investigate mechanical properties of these alloys. Alloys were produced by mechanical alloying under argon atmosphere. Structural, and mechanical properties of these alloys were investigated by means of XRD, SEM and nanoindenter analysis. From the XRD data it is found that as the Ce content increases, the crystallite size also increases. On the other hand, the hardness of the alloys decreases with the increasing Ce content. Indentation results show that the measured hardness displays a peak load dependence. Load-independent hardness was calculated by Hays-Kendall approach. As a results, it was found that Ce-doping modifies the microstructure and hardness of the alloy.
6
Content available remote

Evaluation of Surface Properties of Four Tooth-Colored Restorative Materials

88%
Arslanoglu Z., Altan H., Sahin O., Tekin M., Adigüzel M.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 2B
B-310-B-313
EN
The aim of this study is to compare microhardness, roughness and micromorphology of the examined materials of a newly developed glass carbomer dental filling material to two different resin modified glass ionomers and a glass ionomer dental filling material. Specimens tested were prepared from a glass carbomer without gloss (Glass Carbomer, GCP), a glass carbomer (Glass Carbomer, GCP) with gloss, two different resin modified glass ionomers (Fuji II LC, GC and Riva LC, SDI) and a glass ionomer (Equia, GC). Seven specimens of each material were prepared according to manufacturer's recommendations. After setting, samples were polished and stored in 37°C distilled water for 24 h. Indentation microhardness of examined restorative materials was measured using the Vickers indenters. In addition surface roughness of the materials was measured using surface profilemeter. Surface morphology was analyzed by using scanning electron microscopy. There was a significant difference in microhardness and roughness between the restorative materials (p<0.05). The highest microhardness was measured for Equia and lowest for glass carbomer with gloss. The roughness was fully definite for the glass carbomer with gloss and indefinite for the glass carbomer without gloss. Small cracks and voids were observed in all groups. High viscosity glass ionomer cement Equia exhibits the high physical strength than RMGIC. Gloss application does not influence the hardness behavior of GCP.
7
Content available remote

Nanomechanical Properties of Different Dental Restorative Materials

76%
Altan H., Bilgic F., Arslanoglu Z., Kale E., Köroğlu Kale A., Altan A., Sahin O.
Acta Physica Polonica A
|
2016
|
vol. 130
|
issue 1
394-396
EN
The aim of this study is to determine the hardness and roughness of glass ionomer cement, glass carbomer, and compomer by nanoindentation. Three different dental restorative materials: glass ionomer cement, glass carbomer cement, and compomer were used. Disc specimens (10 mm × 1 mm) were prepared from each material using teflon mold. All specimens were light cured according to the manufacturer's instructions. The specimens were then mounted in polyacrilic resin. After grinding and polishing the specimens were stored in distilled water at 37°C for 1 day. The specimens were investigated using nanoindenter. The highest nanohardness was measured for glass ionomer cement and the lowest for glass carbomer. Regarding roughness, glass ionomer cement and compomer showed the highest mean values. Glass ionomer cement and compomer exhibited similar nanomechanical properties. Glass carbomer had superior ability to be polished up.
8
Content available remote

Mechanical Properties of Nanocrystalline Tetragonal Zirconia Stabilized with CaO, MgO and Y_2O_3

64%
Sahin O., Demirkol İ., Göcmez H., Tuncer M., Ali Cetinkara H., Salih Güder H., Sahin E., Rıza Tuncdemir A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 2
296-298
EN
The citrate gel method, similar to the polymerized complex method, was used to synthesize homogeneous tetragonal zirconia at 1000°C. Nanocrystalline tetragonal phase has been fully stabilized at wide temperature range with 10 mol.% CaO, MgO, and Y_2O_3 addition. Scanning electron microscopy, X-ray diffraction, and microhardness tests are used to characterize synthesized materials. The grain size and dislocation density were calculated from X-ray diffraction data. The examined material exhibits indentation size effect behavior. Results revealed that the Vickers and Knoop microhardness are dependent on indentation test load. Geometrically necessary dislocation model and modified proportional resistance model are used to analyze the load dependence of the microhardness. The highest hardness values were obtained for the samples with CaO addition; however the lowest values were acquired for sample stabilized with Y_2O_3 by using both Knoop and Vickers techniques. This situation might be explained using the Hall-Petch relation.
9
Content available remote

Hardness Behavior of Alumina-Zirconia Nanocomposites Synthesized by Gel Process

64%
Sahin O., Hasde A., Göcmez H., Tuncer M., Ali Cetinkara H., Salih Güder H., Sahin E., Rıza Tuncdemir A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 2
299-301
EN
The alumina-zirconia composites are one of the relatively good and promising candidates for biomaterials application, due to biocompatibility and their mechanical properties that combines high flexural strength with a high toughness. The aim of the present work is to analyze the mechanical properties of these composites, where zirconia content was varied from 5 to 50 wt%. The citrate gel method, similar to the polymerized complex method, was used to synthesize these ceramics. Scanning electron microscopy, X-ray diffraction and microhardness tests are used to characterize synthesized materials. The examined material exhibits the behaviour of indentation size effect. Modified proportional resistance model are used to analyze the load dependence of the microhardness. X-ray diffraction analysis was used to calculation of the grain size and dislocation density. It is found that hardness is decreased when the zirconia content increases with enlargement of grain size.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.