Thermal contact resistance plays a very important role in heat transfer efficiency and thermomechanical coupling response between two materials,and a common method to reduce the thermal contact resistance is to fill a...Thermal contact resistance plays a very important role in heat transfer efficiency and thermomechanical coupling response between two materials,and a common method to reduce the thermal contact resistance is to fill a soft interface material between these two materials.A testing system of high temperature thermal contact resistance based on INSTRON 8874 is established in the present paper,which can achieve 600 C at the interface.Based on this system,the thermal contact resistance between superalloy GH600 material and three-dimensional braid C/C composite material is experimentally investigated,under different interface pressures,interface roughnesses and temperatures,respectively.At the same time,the mechanism of reducing the thermal contact resistance with carbon fiber sheet as interface material is experimentally investigated.Results show that the present testing system is feasible in the experimental research of high temperature thermal contact resistance.展开更多
In view of the M_(n+1)AX_(n)(MAX)phase coatings benefting the adaptive passivation flm for good corrosion resistance and high electronic density of states for excellent electrical conductivity,here,we reported the Cr_...In view of the M_(n+1)AX_(n)(MAX)phase coatings benefting the adaptive passivation flm for good corrosion resistance and high electronic density of states for excellent electrical conductivity,here,we reported the Cr_(2)Al C MAX phase coatings with different preferred orientations by a homemade technique consisting of vacuum arc and magnetron sputtering.The dependence of surface and interface microstructural evolution upon the corrosion and electrochemical properties of deposited coating was focused.Results showed that all the Cr_(2)Al C coatings with different phase orientations greatly improved the performance of stainless steel(SS)316 L substrate.Specifcally,the lowest value of interface contact resistance(ICR)reached to 3.16 mΩcm^(2)and the lowest corrosion current density was 2×10^(-2)μA cm^(-2),which were much better than those of bare SS316L.The combined studies of electrochemical properties and theoretical calculations demonstrated that the Cr_(2)Al C coatings with preferred(103)orientation were easier to form oxide passivation flm on their surface to increase the corrosion resistance.展开更多
Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of t...Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of these laminates,the heat conduction mechanism is more complicated than that of one-layer isotropic media.Analytical solutions are the best ways to study and understand such problems in depth.In this study,different existing analytical solutions for heat conduction in multi-layer and composite materials are reviewed and classified in rectangular,cylindrical,spherical,and conical coordinates.Applied boundary conditions,internal heat source,and thermal contact resistance as the most critical parameters in the solution complexity investigated in the literature,are discussed and summarized in different tables.Various types of multi-layer structures such as isotropic,anisotropic,orthotropic,and reinforced laminates are included in this study.It is found that although more than half a century has passed since the beginning of the research on heat transfer in multi-layer composites,new researches that can help with a better understanding in this area are still being offered.The challenges and shortcomings in this area are also discussed to guide future researches.展开更多
基金supported by the Fundamental Research Funds for the Central Universities (FRF-BR-10-007A and FRF-AS-09-001A)the National Natural Science Foundation of China (10872104)
文摘Thermal contact resistance plays a very important role in heat transfer efficiency and thermomechanical coupling response between two materials,and a common method to reduce the thermal contact resistance is to fill a soft interface material between these two materials.A testing system of high temperature thermal contact resistance based on INSTRON 8874 is established in the present paper,which can achieve 600 C at the interface.Based on this system,the thermal contact resistance between superalloy GH600 material and three-dimensional braid C/C composite material is experimentally investigated,under different interface pressures,interface roughnesses and temperatures,respectively.At the same time,the mechanism of reducing the thermal contact resistance with carbon fiber sheet as interface material is experimentally investigated.Results show that the present testing system is feasible in the experimental research of high temperature thermal contact resistance.
基金fnancially supported by the National Science Found for Distinguished Young Scholars of China(No.52025014)the National Science and Technology Major Project(No.2017VII-0012–0108)+1 种基金the National Science Foundation of China(Nos.51901238 and 52101109)the Natural Science Foundation of Ningbo(Nos.202003N4350 and 202003N4025)。
文摘In view of the M_(n+1)AX_(n)(MAX)phase coatings benefting the adaptive passivation flm for good corrosion resistance and high electronic density of states for excellent electrical conductivity,here,we reported the Cr_(2)Al C MAX phase coatings with different preferred orientations by a homemade technique consisting of vacuum arc and magnetron sputtering.The dependence of surface and interface microstructural evolution upon the corrosion and electrochemical properties of deposited coating was focused.Results showed that all the Cr_(2)Al C coatings with different phase orientations greatly improved the performance of stainless steel(SS)316 L substrate.Specifcally,the lowest value of interface contact resistance(ICR)reached to 3.16 mΩcm^(2)and the lowest corrosion current density was 2×10^(-2)μA cm^(-2),which were much better than those of bare SS316L.The combined studies of electrochemical properties and theoretical calculations demonstrated that the Cr_(2)Al C coatings with preferred(103)orientation were easier to form oxide passivation flm on their surface to increase the corrosion resistance.
基金financial support of the National Natural Science Foundation of China(No.52025061 and No.51961130386)the financial support from the Royal Society-Newton Advanced Fellowship grant(NAF\R1\191163).
文摘Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of these laminates,the heat conduction mechanism is more complicated than that of one-layer isotropic media.Analytical solutions are the best ways to study and understand such problems in depth.In this study,different existing analytical solutions for heat conduction in multi-layer and composite materials are reviewed and classified in rectangular,cylindrical,spherical,and conical coordinates.Applied boundary conditions,internal heat source,and thermal contact resistance as the most critical parameters in the solution complexity investigated in the literature,are discussed and summarized in different tables.Various types of multi-layer structures such as isotropic,anisotropic,orthotropic,and reinforced laminates are included in this study.It is found that although more than half a century has passed since the beginning of the research on heat transfer in multi-layer composites,new researches that can help with a better understanding in this area are still being offered.The challenges and shortcomings in this area are also discussed to guide future researches.
