The Examination of the laboratory anxiety, state and trait anxiety of university students in high voltage laboratory

With this study were aimed the investigation of the state and trait anxiety levels of Electric-Electronic Engineering students on High Voltage Laboratory anxiety. This research is designed as relational scanning model. The samples of the study comprised 113 students from Electric-Electronic Engineering in Engineering Faculty. In the study; “High Voltage Laboratory Anxiety Scale” with three factors which was developed by Güneş and Özsoy-Güneş (2015) and “The State and Trait Anxiety Scale” was developed by Spielberger and his colleagues (1970), adapted to Turkish by Öner and Le Compte (1985) are used as tool of data collection. In order to analyze the data, SPSS 20.00, Pearson correlation coefficient techniques and regression analysis techniques are used. At the end of the study, between all scales has a positive relation. Multiple linear regression analysis showed that the trait anxiety and laboratory anxiety of students has been found to be effective on the state anxiety of students

Wear behaviour of plasma paste boronized of AISI 8620 steel with borax and B2O3 paste mixtures

In the present study, AISI 8620 steel was plasma paste boronized (PPB) by using paste mixtures with different borax and B2O3 percentages. The PPB process was carried out in a DC plasma system at 973, 1023 and 1073 K for 5 h in a gas mixture with 70% H2–30% Ar under a constant pressure of 103 Pa (10 mbar). The thickness of boride layers ranged from 15.9 to 53.6 μm depending on the temperature and process time. The hardness of the borides formed on the surface of the steel substrate and unborided steel substrate were 1648–1924 HV0.05 and 226 HV0.05, respectively. X-ray diffraction analysis of the boride layers on the surface of the samples were obtained for FeB and Fe2B phases. The wear tests on the steel were performed by using a ball-on-disc test device at room temperature with applied load of 10 N and with a shear velocity of 0.2 m/s. Wear test results showed that the highest value of wear rate was observed in the unborided sample while the lowest wear rate was observed in the PPB samples with 30% borax + 70% B4C paste at 1073 K for 5 h.National Boron Research Institute (No. 2009-Ç0246)

Kinetics of borided gear steels

In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigate

Investigation of surface properties and wear resistance of borided steels with different B4C mixtures

Boriding is a thermo-chemical surface hardening treatment applied to iron based materials. This treatment is performed by boron element diffusing into iron based materials at high temperatures. Wear resistance increases by forming ferro-boron phases on the material surface. In addition, a very hard layer forms on the material surface. As a result, the tribological properties of the material increase. In this study, 6 different mixtures are prepared with B4C and SiC powders. In these mixtures steels of AISI 1020 and AISI 1040 are borided with a stainless steel crucible at a temperature of 900°C for 3 h. Depending on the boriding mixtures, the thickness of the borides formed on the surface of borided AISI 1020 and AISI 1040 steels ranged from 14 to 71 μm and from 10 to 64 μm, respectively. It is observed that the layer thickness increases with increase in B4C% ratio. The wear rate of steels increased with decreasing SiC ratio. The average value of obtained microhardness for borides of AISI 1020 and AISI 1040 steels are 1776 and 1860 HV0.05, respectively (17) (PDF) Investigation of surface properties and wear resistance of borided steels with different B4C mixtures. Available from: https://www.researchgate.net/publication/286196539_Investigation_of_surface_properties_and_wear_resistance_of_borided_steels_with_different_B4C_mixtures [accessed Jan 12 2020]

Investigation of tribological behaviour of plasma paste boronized of AISI 8620, 52100 and 440C steels

In the present study, AISI 8620, 52100 and 440C steels were plasma paste boronized (PPB) by using 100% borax paste. PPB process was carried out in a dc plasma system at temperature of 700 and 800 °C for 3 and 5 h in a gas mixture of 70%H2–30%Ar under a constant pressure of 4 mbar. The properties of boride layer were evaluated by optical microscopy, X-ray diffraction and Vickers micro-hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed FeB and Fe2B phases for 52100 and 8620 steels and FeB, Fe2B, CrB and Cr2B borides for 440C steel. PPB process showed that since the plasma activated the chemical reaction more, a thicker boride layer was formed than conventional boronizing methods at similar temperatures. It was possible to establish boride layer with the same thickness at lower temperatures in plasma environment by using borax paste

Plasma paste boronizing of AISI 8620, 52100 and 440C steels

In the present study, AISI 8620, 52100 and 440C steels were plasma paste boronized (PPB) by using 100% borax paste. PPB process was carried out in a dc plasma system at temperature of 700 and 800 °C for 3 and 5 h in a gas mixture of 70%H2–30%Ar under a constant pressure of 4 mbar. The properties of boride layer were evaluated by optical microscopy, X-ray diffraction and Vickers micro-hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed FeB and Fe2B phases for 52100 and 8620 steels and FeB, Fe2B, CrB and Cr2B borides for 440C steel. PPB process showed that since the plasma activated the chemical reaction more, a thicker boride layer was formed than conventional boronizing methods at similar temperatures. It was possible to establish boride layer with the same thickness at lower temperatures in plasma environment by using borax paste

Kinetics of plasma paste boronized AISI 8620 steel in borax paste mixtures

In the present study, AISI 8620 steel was plasma paste boronized by using various borax paste mix tures. The plasma paste boronizing process was carried out in a dc plasma system at a temperature of 973, 1023 and 1073 K for 2, 5 and 7 h respectively in a gas mixture of 70% H2–30% Ar under a constant pressure of 10 mbar. The properties of the boride layer were evaluated by optical microscopy, Xray diffraction, the microVickers hardness tester and the growth kinetics of the boride layers. The thickness of the boride layersvaried from 14 to 91 μm depending on the boronizing time and temperature. Xray diffraction analysis of boride layers on the surface of the steel revealed the formation of FeB and Fe2B phases. Depending on the temperature and layer thickness, the activation energies of boron in steel were found to be 99.773 kJ/mol for 100% borax paste.National BoronResearch Institute as BOREN project numbered“2009-Ç0246

Investigation of adhesion and tribological behavior of borided aısı 310 stainless steel

In the present study, the effects of the boriding process on adhesion and tribological properties of AISI 310 steel were investigated. Boriding was performed in a solid medium consisting of Ekabor-II powders at 1123 and 1323K for 2 and 6 h. The boride layer was characterized by optical microscopy, the X-ray diffraction technique and the micro-Vickers hardness tester. The X-ray diffraction analysis of the boride layers on the surface of the steels revealed the existence of FexBy, CrxBy and NixBy compounds. Depending on the chemical composition of substrates, the boride layer thickness on the surface of the AISI 310 steel was found to be 56.74 μm. The hardness of the boride compounds formed on the surface of the AISI 310 steel ranged from 1658 to 2284 HV0,1, whereas the Vickers hardness value of the untreated steel AISI 310 was 276 HV0,1. The wear tests were carried out in a ball-disc arrangement under a dry friction condition at room temperature with an applied load of 10N and with a sliding speed of 0.3 m/s, at a sliding distance of 1000m. The wear surfaces of the steel were analyzed using an SEM microscopy and X-ray energy dispersive spectroscopy EDS. It was observed that the wear rate of unborided and borided AISI 310 steel ranged from 4.57 to 71.42 mm3/Nm

Correlation of Standard and Cone Penetration Tests: Case Study from Tekirdag (Turkey)

World Multidisciplinary Civil Engineering-Architecture-Urban Planning Symposium (WMCAUS) -- JUN 12-16, 2017 -- Prague, CZECH REPUBLICIn geotechnical engineering, the Standard Penetration Test (SPT-N value) is often used as an in-situ test. The Cone Penetration Test (CPT) is based on design and cone resistance (qc) and is becoming increasingly widespread. However, there is also a need for a SPT-CPT correlation association that can be used in the basic design. In this study, the values of the SPT-CPT tests applied to the ground were compared and tried to generate a certain statistical data. SPT and CPT experiments were performed side by side to determine the soil properties. Formulas have been developed using various statistical methods and correlation coefficients have been established between the data obtained for high-medium-low plastic clay and sand and sandy clayey soils. The obtained data were compared with the studies in the literature

Investigation of wear behavior of borided dın x15crnisi25 steel

In the present study, effect of the boriding process on adhesion and tribological properties of DIN X15CrNiSi25 steel has been investigated. Boriding was performed in a solid medium consisting of Ekabor- II powders at 1123 and 1323K for 2 and 6 h. The boride layer was characterized by optical microscopy, Xray diffraction technique and the micro-Vickers hardness tester. . X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FexBy, CrxBy and NixBy compounds. Depending on the chemical composition of substrates, the boride layer thickness on the surface of the X15CrNiSi25 steel was found to be 56.74 μm. The hardness of the boride compounds formed on the surface of the X15CrNiSi25 steel ranged from 1658 to 2284 HV0,1, whereas Vickers hardness values of the untreated steel X15CrNiSi25 were 276 HV0,1. The wear tests were carried out in a ball-disc arrangement under a dry friction condition at room temperature with an applied load of 10N and with a sliding speed of 0.3 m/sec at a sliding distance of 1000m. The wear surfaces of the steel were analyzed using a SEM microscopy and X-ray energy dispersive spectroscopy EDS. It was observed that the wear rate of unborided and borided X15CrNiSi25 steel ranged from 4.57 to 71.42 mm3/Nm