Calcium-magnesium-alumina-silicate(CMAS)corrosion has attracted special attention in the thermal barrier coating(TBC)*** high temperatures,when CMAS melts,it adheres to the coating surface and penetrates the interior,...
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Calcium-magnesium-alumina-silicate(CMAS)corrosion has attracted special attention in the thermal barrier coating(TBC)*** high temperatures,when CMAS melts,it adheres to the coating surface and penetrates the interior,severely destroying the *** this study,a promising CMAS-phobic and infiltration-inhibiting material,GdPO4,on which molten CMAs is difficult to wet and penetrate,was *** desirable attributes are explained by analyzing the material characteristics of GdPO_(4) and its interfacial reaction with ***4 is demonstrated to have low surface energy,making it difficult for molten CMAS to wet and adhere to the *** in contact with molten CMAS,a double-layer structured reaction layer consisting of an acicular upper sublayer and a compact lower sublayer is formed on the GdPO4 surface,which can effectively impede molten CMAS spreading and ***-principles calculation results revealed that the reaction layer has low surface energy and low adhesion to CMAS,which are favorable for molten CMAS ***,the formation of the reaction layer increases the viscosity of the molten CMAS,which can increase melt wetting and ***,GdPO4,which exhibits excellent CMAS-phobicity and infiltration-inhibiting ability,is a promising protective layer material for TBCs against CMAS adhesion and attack.
To utilize Cu-benzene-1,3,5-tricarboxylate(Cu-BTC)adsorbed lubricant oils in the self-lubricating field,the adsorption properties of Cu-BTC on different 1-olefins must be *** this work,1-hexene,1-octene,1-nonene,1-dec...
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To utilize Cu-benzene-1,3,5-tricarboxylate(Cu-BTC)adsorbed lubricant oils in the self-lubricating field,the adsorption properties of Cu-BTC on different 1-olefins must be *** this work,1-hexene,1-octene,1-nonene,1-decene,1-undecene,and 1-dodecene were studied by the Monte Carlo method and *** adsorption limit of Cu-BTC for n-olefins was determined as 1-undecene by the adsorption *** suggested a limit for even straight-chain molecules to the adsorption of *** maximum ratio of the olefin length of the largest pore diameter(L/D)of Cu-BTC was approximately ***,theoretical calculations(radial distribution function(RDF))and experiments(infrared(IR)spectra)confirmed the interaction of n-olefin adsorbates and the Cu-BTC framework occurred between the-CH=of olefins and the Cu and O atoms of the Cu-BTC *** work adds to the understanding and investigation of the adsorption of liquid lubricants using Cu-BTC as a metal-organic framework(MOF).
The high temperature fire retardancy of titanium alloy is an important factor restricting its application in aero-engine,and the laser ignition method can accurately reflect the fire retardancy of titanium alloy under...
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The high temperature fire retardancy of titanium alloy is an important factor restricting its application in aero-engine,and the laser ignition method can accurately reflect the fire retardancy of titanium alloy under local *** to the limitations of laser ignition experiments on the microscopic boundary and the transient propagation mechanism of the temperature field,molecular dynamics(MD)simulations and JMatPro calculation were applied to study the temperature field of Ti-6Al and Ti-48Al *** results show that a molten pool is formed on the surface of Ti-Al alloys under continuous laser irradiation,and the temperature field of the molten pool is normally distributed from the center to the *** the center temperature reaches the critical point of ignition,the extended combustion occurs,and the extended combustion path advances along the direction of the air *** with Ti-6Al alloy,Ti-48Al alloy has higher fire retardancy under laser *** is due to the better heat transfer performance of Ti-48Al,which leads to the weakening of the heat concentration effect near the boundary of the spot temperature *** it is necessary to increase the partial pressure of oxygen,and thus to reduce the ignition point of the alloy in order to achieve the ignition boundary condition of Ti-48Al alloy under the same laser heat *** the aspect of extended combustion path,the boundary heat collection effect of specimens shown by MD models reveals another mechanism affecting combustion expansion path besides the direction of air *** is,the heat generated by the laser spot is interrupted when it is transmitted to the boundary of the specimen along the short side direction,resulting in a concentration of heat near the *** the combustion path also tends to expand along this direction.
At present, most of the existing methods combine the data from different views mechanically to obtain the latent subspace with complementary information, which not only fails to make full use of the data information f...
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In this study, effects of initial orientation on microstructure evolution and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding(AEB) was systematically studied. The samples with RD and TD...
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In this study, effects of initial orientation on microstructure evolution and mechanical properties of AZ31 Mg alloy sheets via accumulated extrusion bonding(AEB) was systematically studied. The samples with RD and TD parallel to extrusion direction(ED) were labeled as RED and TED, respectively. RD and TD pieces alternately stacked was named as RTED. The results revealed that under three-dimensional compressive stress, {10-12} tensile twinning dominated the first stage deformation in container. As the plunger continuous press down, dynamic recrystallization(DRX) occurred, and the newly fine DRXed grains along original and twin grain boundaries gradually consumed the matrix and twin grains. The microstructure was completely transformed into recrystallized grain structure at sizing band with an average grain size of ~0.9 μm in TED sample, smaller than that of RED *** the alloys extruded out of the die, DRXed grains significantly grew to ~4.5 μm and 3.5 μm for RED and TED samples, respectively. A laminated microstructure was obtained with average grain sizes of~4.4 μm in RD layers and 3.5 μm in TD layers for RTED sample. The AEB processed samples exhibited an ED-tilt double-peak basal texture with similar texture intensity. The tensile tests results indicated that attributed to the combined effect of grain refinement and texture evolution, the yield strength and fracture elongation of RED and TED samples was significantly improved. The heterogeneous microstructure in RTED sample induced an extra work hardening(HDI-work hardening) in tensile deformation and resulted in a further improved elongation of 32.0%.
The recent transport measurements of La_(3)Ni_(2)O_(7)uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature(P-T)phase *** by this,we perform theoretical first-principles studies of...
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The recent transport measurements of La_(3)Ni_(2)O_(7)uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature(P-T)phase *** by this,we perform theoretical first-principles studies of La_(3)Ni_(2)O_(7)with the pressure ranging from 0 to 100 ***,we reveal a pressure dependence of the Ni-d_(z^(2))electron density at the Fermi energy(n_(z)^(E_(F)))that highly coincides with such *** this basis,we further explore the electronic structure under uniaxial *** tracking the stress response of n_(z)^(E_(F)),we propose that superconductivity can be achieved by applying only ~2GPa of compression along the c *** idea is further exemplified from the perspectives of lattice distortion,band structure,Fermi surface and superconducting phase *** also discuss the possible charge modulation under the stress and provide an insight into the relation between nz E Fand the superconducting T_(c)in La_(3)Ni_(2)O_(7)*** study provides new routes to the search of high-T_(c)superconductors in future experiments.
In this paper, we propose a boosted proximal difference-of-convex algorithm for solving a minimization problem composed of the sum of a smooth convex function and a continuously differentiable convex function minus a ...
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In this work, a novel surface strengthening strategy for Mg-Li alloys was proposed, called cold spraying assisted high-speed laser cladding. CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold s...
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A radar-infrared compatible stealth surface is designed and *** modifying the radar absorbing material(RAM),the design can theoretically achieve radar-infrared compatibility and broadband radar absorption through surf...
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A radar-infrared compatible stealth surface is designed and *** modifying the radar absorbing material(RAM),the design can theoretically achieve radar-infrared compatibility and broadband radar absorption through surface patterns and structures.A transmission-line-based model(TLM)is developed to analyze the radar absorbing performance of the *** of the structure geometries is conducted aiming to maximize the-10 d B absorption bandwidth in 2–18 *** with optimized structure geometries exhibits a superior absorption bandwidth,more than twice the bandwidth of the original 1.5 mm RAM slab,while maintaining a relatively low infrared emissivity.
LaMnO_(3)perovskite has great potential in microwave absorption at high temperature due to its complex doping effect and super *** current research mainly focuses on the doping ratio regulation,while the mechanism of ...
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LaMnO_(3)perovskite has great potential in microwave absorption at high temperature due to its complex doping effect and super *** current research mainly focuses on the doping ratio regulation,while the mechanism of doping effect at high temperature is still lack of sufficient *** this work,La1−xSrxMn1−yFeyO_(3)(LaMnO_(3),La_(0.7)Sr_(0.3)MnO_(3),and La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3))nanostructures with different doping sites were successfully prepared by the solid phase reaction ***,the high temperature dielectric test samples were obtained by mixing with cordierite(2MgO·2Al_(2)O_(3)·5SiO_(2)(MAS)).The results showed that the temperature dependence of Mn ion spin state had a significant impact on the high temperature dielectric behavior of La_(1−x)Sr_(x)Mn_(1−y)FeyO_(3).Particularly,when the thickness is only 1.9 mm,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS can achieve the widest bandwidth of 4.2 GHz covered the entire X-band(8.2–12.4 GHz)and a minimum reflection loss(RL)value of−17.99 dB at 500℃.In order to improve the operating temperature of La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS,a cellular array structure was designed by using computer simulationtechnology(CST)software to introduce magnetic *** the outer length of the hexagon is 1 mm and the coating thickness is 1.9 mm,the widest bandwidth covers the X-band and the minimum RL value is−15.35 dB at 800℃.Therefore,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)has a great prospect as an efficient high temperature microwave absorber.
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