Zn-5wt% Al eutectic alloy was directionally solidified with different growth rates （5.32-250.0μm/s） at a constant temperature gradient of 8.50 K/mm using a Bridgman-type growth apparatus.The values of eutectic spac...Zn-5wt% Al eutectic alloy was directionally solidified with different growth rates （5.32-250.0μm/s） at a constant temperature gradient of 8.50 K/mm using a Bridgman-type growth apparatus.The values of eutectic spacing were measured from transverse sections of the samples.The dependences of the eutectic spacing and undercooling on growth rate are determined as λ=9.21V-0.53 and ΔT=0.0245V0.53,respectively.The results obtained in this work were compared with the Jackson-Hunt eutectic theory and the similar experimental results in the literature.Microhardness of directionally solidified samples was also measured by using a microhardness test device.The dependency of the microhardness on growth rate is found as Hv=115.64V0.13.Afterwards,the electrical resistivity （r） of the casting alloy changes from 40×10-9 to 108×10-9 Ω·m with the temperature rising in the range of 300-630 K.The enthalpy of fusion （ΔH） and specific heat （Cp） for the Zn-Al eutectic alloy are calculated to be 113.37 J/g and 0.309 J/（g·K）,respectively by means of differential scanning calorimetry （DSC） from heating trace during the transformation from liquid to solid.展开更多
Normal,R0,and anomalous,RS,components of the Hall coefficient are determined from the results of experimental investigations of temperature dependences of the Hall coefficient,magnetic susceptibility,and specific elec...Normal,R0,and anomalous,RS,components of the Hall coefficient are determined from the results of experimental investigations of temperature dependences of the Hall coefficient,magnetic susceptibility,and specific electrical resistance for intermetallic Gd3In,Gd3In5 and GdIn3 compounds.Effective parameters of spin-orbital interactionλSO of intermetallic compounds are calculated from anomalous components RS of the Hall coefficient and specific electrical resistance.The results calculated for the band parameters and effective parameters of spin-orbital interactionλSO for Gd-In system intermetallides coincide by orders of magnitude with the results obtained from the optical spectra of pure REMs(rare-earth metals).展开更多
This paper demonstrates the influence of deposition parameters(temperature,power and time)and stoichiometric composition of thin aluminum nitride(AIN)coatings,the thickness of which varied from 320 to 1100 nm deposite...This paper demonstrates the influence of deposition parameters(temperature,power and time)and stoichiometric composition of thin aluminum nitride(AIN)coatings,the thickness of which varied from 320 to 1100 nm deposited by DC reactive magnetron sputtering on their microstructure,mechanical and microtribological properties.The investigation revealed that high-deposition power(150W)and temperature(200℃)lead to sputtering of coatings with high roughness,low mechanical and high microtribological properties.Such a phenomenon occurred due to the formation of a coarse-grained structure,high porosity and dendritic growth of the coating,which was observed on their cross-sections.Reducing the deposition temperature to 20℃and power to 80-100 W allowed to obtain a fine-crystalline structure demonstrating low-roughness values with crystallites evenly and compactly distributed over the surface.Such coatings showed higher mechanical and low microtribological properties.Surface resistivity was lower on coatings with a fine crystalline structure and correlated with the nitrogen content of the coating.In the course of the research,it was demonstrated that the optimal combination of microstructure,mechanical,microtribological properties and electrical resistivity for practical use in micro-and nanosensory applications may be achieved for the AIN coating with the thickness of 320 nm and 29.71 at.%N,deposited at 20℃,100 W and 20min.Such a coating possesses the highest values of mechanical properties,low roughness and specific surface resistance,as well as low coefficient of friction and specific volumetric wear compared toall coatings under study.展开更多
基金supported by Erciyes University Scientific Research Project Unit (No.FBA-10-3376)
文摘Zn-5wt% Al eutectic alloy was directionally solidified with different growth rates （5.32-250.0μm/s） at a constant temperature gradient of 8.50 K/mm using a Bridgman-type growth apparatus.The values of eutectic spacing were measured from transverse sections of the samples.The dependences of the eutectic spacing and undercooling on growth rate are determined as λ=9.21V-0.53 and ΔT=0.0245V0.53,respectively.The results obtained in this work were compared with the Jackson-Hunt eutectic theory and the similar experimental results in the literature.Microhardness of directionally solidified samples was also measured by using a microhardness test device.The dependency of the microhardness on growth rate is found as Hv=115.64V0.13.Afterwards,the electrical resistivity （r） of the casting alloy changes from 40×10-9 to 108×10-9 Ω·m with the temperature rising in the range of 300-630 K.The enthalpy of fusion （ΔH） and specific heat （Cp） for the Zn-Al eutectic alloy are calculated to be 113.37 J/g and 0.309 J/（g·K）,respectively by means of differential scanning calorimetry （DSC） from heating trace during the transformation from liquid to solid.
文摘Normal,R0,and anomalous,RS,components of the Hall coefficient are determined from the results of experimental investigations of temperature dependences of the Hall coefficient,magnetic susceptibility,and specific electrical resistance for intermetallic Gd3In,Gd3In5 and GdIn3 compounds.Effective parameters of spin-orbital interactionλSO of intermetallic compounds are calculated from anomalous components RS of the Hall coefficient and specific electrical resistance.The results calculated for the band parameters and effective parameters of spin-orbital interactionλSO for Gd-In system intermetallides coincide by orders of magnitude with the results obtained from the optical spectra of pure REMs(rare-earth metals).
基金support of the Belarus Republican Foundation for Fundamental Research(Grant Nos.T23RNF-132 and T17KIG-009)Nikolaev A.acknowledges the support of the Russian Science Foundation(Grant No.23-49-10062,https://rscf.ru/project/23-49-10062/).
文摘This paper demonstrates the influence of deposition parameters(temperature,power and time)and stoichiometric composition of thin aluminum nitride(AIN)coatings,the thickness of which varied from 320 to 1100 nm deposited by DC reactive magnetron sputtering on their microstructure,mechanical and microtribological properties.The investigation revealed that high-deposition power(150W)and temperature(200℃)lead to sputtering of coatings with high roughness,low mechanical and high microtribological properties.Such a phenomenon occurred due to the formation of a coarse-grained structure,high porosity and dendritic growth of the coating,which was observed on their cross-sections.Reducing the deposition temperature to 20℃and power to 80-100 W allowed to obtain a fine-crystalline structure demonstrating low-roughness values with crystallites evenly and compactly distributed over the surface.Such coatings showed higher mechanical and low microtribological properties.Surface resistivity was lower on coatings with a fine crystalline structure and correlated with the nitrogen content of the coating.In the course of the research,it was demonstrated that the optimal combination of microstructure,mechanical,microtribological properties and electrical resistivity for practical use in micro-and nanosensory applications may be achieved for the AIN coating with the thickness of 320 nm and 29.71 at.%N,deposited at 20℃,100 W and 20min.Such a coating possesses the highest values of mechanical properties,low roughness and specific surface resistance,as well as low coefficient of friction and specific volumetric wear compared toall coatings under study.
