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Porous carbon materials have been widely used for the removal of SO2 from flue gas. The main objective of this work is to clarify the effects of adsorption temperature on SO2 adsorption and desorption energy consumption. Coal-based porous powdered activated coke (PPAC) prepared in the drop-tube reactor was used in this study. The N2 adsorption measurements and Fourier transform infrared spectrometer analysis show that PPAC exhibits a developed pore structure and rich functional groups. The experimental results show that with a decrease in adsorption temperature in the range of 50–150 °C, the adsorption capacity of SO2 increases linearly; meanwhile, the adsorption capacity of H2O increases, resulting in the increase in desorption energy consumption per unit mass of adsorbent. The processes of SO2 and H2O desorption were determined by the temperature-programmed desorption test, and the desorption energies for each species were calculated. Considering the energy consumption per unit of desorption and the total amount of adsorbent, the optimal adsorption temperature yielding the minimum total energy consumption of regeneration is calculated. This study systematically demonstrates the effect of adsorption temperature on the adsorption–desorption process, providing a basis for energy saving and emission reduction in desulfurization system design.

To explore the effects of aging and irradiation on the formation of solute clusters, Fe-2.8Ni-2.0Al (at.%) alloys after solid-solution treatment were aged at 500 ℃ for 16 h and 32 h and irradiated with Ar ions to the fluence of 4 × 1016 ions·cm−2 at 290 ℃, respectively. Transmission electron microscope and atom probe tomography were used to characterize the microstructure and solute atoms distribution. Results showed that B2-NiAl clusters were formed in aged alloys and the number density increased with time. The number density of clusters was 8.35 × 1022 m−3 after 32 h at 500 ℃ aging. However, high number density of dislocation loops and B2-FeNi clusters were found after irradiation at 290 ℃. The number density of clusters reached to 3.61 × 1023 m−3. The nucleation of B2-NiAl clusters under aging is driven by the phase transform free energy with the lower mixing enthalpy of Ni and Al atoms, while the formation of B2-FeNi clusters is due to the combination of the interaction between dislocation loops and Ni solutes with the enhanced diffusion rate of Ni atoms due to supersaturated vacancy.

Cu–Fe alloys with different Fe contents were prepared by vacuum hot pressing. After hot rolling and aging treatment, the effects of Fe content on microstructure, mechanical properties and electrical conductivity of Cu–Fe alloys were studied. The results show that, when w(Fe)

Hot compression deformation behavior of the Cu-0.45Cr-1.0Ni-0.28Si-0.14Co alloy was studied by a thermal-mechanical simulator at strain rates of 0.001–1 s−1 and deformation temperatures of 700–900°C. The microstructure and texture of the copper alloy after the hot compression deformation were investigated. The results showed that the flow behavior of the Cu-Cr-Ni-Si-Co alloy was significantly affected by the deformation temperature and strain rate. The typical dynamic recrystallization (DRX) occurred at high temperatures and low strain rates, while the typical dynamic recovery (DRV) appeared at low temperatures and high strain rates. When the deformation temperature increased from 700°C to 900°C, a transition from copper and S texture to gross texture was found. The value of hot deformation activation energy (Q) was calculated as 330.87 kJ/mol. The optimized hot deformation parameters for the Cu-Cr-Ni-Si-Co alloy were 800–850°C/0.01–0.1 s−1.

Denitration (De-NO x ) over activated cokes (ACs) for sintering flue gas needs intensification. Gaseous reactions in a gas mixture containing NO, NO2, and NH3, with the effect of O2 concentration and moisture, were taken into consideration in the study of NO x conversion over ACs. Experimental studies on NO x conversion with and without NH3 over ACs were conducted using a fixed-bed reactor at 100 °C. The results demonstrated that moisture significantly affected NO x removal over ACs, especially the NO2 conversion. Under dry conditions, a disproportionation reaction of NO2 over ACs dominated NO x conversion with no NH3, whereas apparent fast selective catalytic reduction (SCR) over the ACs was observed in the presence of NH3. Regardless of the presence of absence of NH3 in wet mixtures, NO2 adsorption on ACs via the disproportionation route dominated the NO x conversion. Increasing the NO2/NO ratio in the simulated flue gas enhanced the NO x conversion rate over ACs. -C(ONO2) deposition on ACs generated by the disproportionation route inhibited NO x conversion with time. O3 oxidation was found to be efficient in increasing the NO2/NO ratio and intensifying the NO x conversion compared with commercially direct NH3-SCR over ACs. Increasing the temperature and decreasing the gas hourly space velocity can promote NO x conversion over ACs after O3 oxidation. NO oxidized with O3 coupled with NH3 spray and continuous regeneration of ACs is a potential method for removing NO x from sintering flue gas.

The corrosion behavior of a copper-based shape memory alloy (Cu−Al−Mn−Zn−Zr) in 3.5 wt.% NaCl solution was investigated by means of potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). At the beginning of corrosion, oxidation products formed on the surface of the shape memory alloy and constantly covered the reaction surface, resulting in the decrease of corrosion rate. After 4 d of immersion in NaCl solution, the corrosion product layer became thick and porous, leading to the increase of corrosion rate, and the corrosion reaction mechanism changed from polarization control to diffusion control. The diffusion impedance increased with increasing thickness of the oxide layer for the samples immersed in NaCl solution for 6−15 d. During the whole corrosion process, the reaction mechanism of the alloy changed and the corrosion resistance was improved continuously. The corrosion products mainly contained CuO, ZnO, Al2O3, MnO/Mn2O3, MnO2 and Al(OH)3. Transition of the corrosion products from Cu2O to CuO and Al2O3 to Al(OH)3 occurred during corrosion.

The corrosion behavior of imitation-gold Cu-Zn-Ni-Sn alloys with and without Al was investigated by means of color difference testing, static corrosion measurements, scanning electron microscopy analysis, electrochemical impedance measurements, and x-ray photoelectron spectroscopy analysis. The results showed that aluminum inhibited dissolution of Zn and Sn by the formation of an oxide film on the surface of the Cu-Zn-Ni-Sn alloy during corrosion, effectively improving its corrosion resistance. A transition of the corrosion product from Cu2O and Cu(OH)2 to CuO occurred on the surface of Cu-Zn-Ni-Sn-Al alloy, and the corrosion rate of the alloy decreased with increasing corrosion time due to the formation of the oxidation film and the hydrophobic effect of Zn5(CO3)2(OH)6 in the product layer.

Cu-TiNi composites with TiNi volume percentages of 1%, 5%, 10% and 15% were prepared by vacuum hot pressing and hot extrusion. The microstructure, thermal and mechanical properties of the composites were analyzed. The results show that diffusion of elements occurred at the interface between the Cu matrix and the TiNi particles during the preparation process, leading to the formation of a (CuNi)Ti diffusion layer. The TiNi particles are uniformly distributed in the Cu-TiNi composites, with a well-bonded interface with the Cu matrix. Cu matrix has major + minor fiber textures after hot extrusion. There is a semi-coherent relationship between the Cu matrix and the (CuNi)Ti phase, with an orientation relationship of (111)Cu∥(103)(CuNi)Ti and an angle of 18.7° between the two crystal planes. Both the Vickers hardness and the compressive yield strength of the Cu-TiNi composites increased with increasing the volume percentage of the TiNi particles, while the thermal expansion coefficient showed an opposite trend. The thermal expansion coefficient, Vickers hardness and compressive yield strength of the Cu-15% TiNi composite are 14.11×10-6 /K, 154.4 Hv and 460.0 MPa, respectively.

The hot compression deformation behavior of Cu–3Ti–0.1Zr alloy with the ultra-high strength and good electrical conductivity was investigated on a Gleeble–3500 thermal-mechanical simulator at temperatures from 700 to 850 °C with the strain rates between 0.001 and 1 s−1. The results show that work hardening, dynamic recovery and dynamic recrystallization occur in the alloy during hot deformation. The hot compression constitutive equation at a true strain of 0.8 is constructed and the apparent activation energy of hot compression deformation Q is about 319.56 kJ/mol. The theoretic flow stress calculated by the constructed constitutive equation is consistent with the experimental result, and the hot processing maps are established based on the dynamic material model. The optimal hot deformation temperature range is between 775 and 850 °C and the strain rate range is between 0.001 and 0.01 s−1.

To study the effects of ion irradiation on hardening and microstructural evolution of solute clusters in Fe-based alloys, Fe-Cu alloy was irradiated with 2.0 MeV He ions to a fluence of 1.0 × 1017 ions cm−2 at 563 K. Nanoindentation and atom probe tomography (APT) were used to characterize the hardness and solute distributions, respectively. Correlation between the mechanical property and microstructure was also discussed. Nanoindentation results showed that the irradiation-induced hardening quickly increased as irradiation depth/damage increased at first and then slowly reached saturation at shallower depth. APT results also showed that well-defined Cu clusters were precipitated after irradiation and grown to a clear saturation at about 0.05 dpa, but the precipitation was suppressed slightly at higher damage/damage rate due to cascade mixing. The good agreement between calculated strength and measured strength demonstrates that the Cu culsters are the dominant feature for hardening.

The ultra-high strength Cu-20Ni-20Mn alloy was prepared by vacuum melting and its mechanical property and corrosion behavior were investigated. After thermomechanical treatment, the alloy exhibited an ultra-high tensile strength of 1204 MPa and the applicable elongation of up to 6.2%. With the increasing exposure time in 3.5% NaCl solution, the corrosion current of the alloy decreased, while the polarization resistance and the charge-transfer resistance of the corrosion surface increased. The corrosion products formed on the surface of the alloy exposed for 1 d, and further corrosion made the corrosion product layer much dense, increasing the corrosion resistance and protecting the alloy from further corrosion.

The copper–graphite metal matrix composites were prepared by powder metallurgy method using cuprous oxide and graphite as the raw materials. Their microstructure, relative density, hardness, electrical resistivity and the compressive strength of the cuprous oxide–graphite (Cu2O-Gr) composites were studied. This composite when compared with copper–graphite (Cu-Gr) composites using copper powder and graphite demonstrated that the new composite had finer microstructures with increased to the higher compression strength value. The Brinell hardness is about 1.5-1.6 times higher than the original material and the compressive strength increased by 50-100 MPa. The good parameters can be attributed to the redox reaction that occurs at the interface between cuprous oxide and graphite particles, resulting in uniform distribution of the reinforcements in matrix and strong interfacial bonding between the copper matrix and the graphite particles.

Copper alloys exhibit a positive thermal expansion effect, which is undesirable to materials as in service, while TiNi composite materials exhibit negative thermal expansion. In this study, we fabricated a new high-density Cu/TiNi composite with low thermal expansion through electroless deposition and powder metallurgy. Mixed powders of 15% electroless deposited Cu-TiNi composite powders, and 85% prepared Cu powders were cold extruded, vacuum hot press heat-treated, and hot compressed at 900°C for 2 h. The coefficients of thermal expansion of the Cu/TiNi composite at 100°C, 200°C, and 300°C were 13.99 × 10−6/K, 17.28 × 10−6/K, and 17.72 × 10−6/K, respectively. The fabricated Cu/TiNi composite materials showed good air-tightness and negative thermal expansion, so have bright prospects in lead frames and other electrical and electronic applications.

Two group of CNT/polydimethylsiloxane flexible films were spin coated by using two kinds of CNTs with different length and same aspect ratio. Results shows that the film conductivity decreases as the film thickness decreases, while the film thickness is less than 40 times of the CNT length. And the downward trend of two groups of films are different. Besides, CNT junctions with structure distortion were well observed experimentally. By introducing CNT structure distortion, film size effect and interface constraint effect into the percolation network model, Monte Carlo simulation results can well fit the experimental data. Simulation results show that the decrease in film conductivity is mainly due to the film size effect. And the interface constraint effect is more obverse for the film prepared by long tubes, which lead to a different downward trend between two groups of films. The influence of some important experimental parameters on the film conductivity are also obtained through calculation. All of these experiment and simulation results could benefit for design of flexible conductive films.

To solve the problem of processing of refractory iron oxide ore resulted from its fine-grained disseminated structure, in this paper, an improved technology was innovatively proposed, which consisted of three stages of reduction roasting-acid leaching followed by magnetic separation, and CaCO3 was introduced during roasting process. Mechanism analyses indicated that kaolinite, a major gangue in ore, can be thermally dehydrated to amorphous metakaolin during roasting process, and CaCO3 can in part react with metakaolin——converting the stable kaolinite gangue mineral into acid-soluble Ca3Al2(SiO4)3, and subsequently Ca3Al2(SiO4)3 was selectively removed by acid leaching process. Moreover, the presence of CaCO3 can also improve the gathering state of Fe-rich particles, which is beneficial for magnetic separation. Iron concentrate obtained via the proposed technology contained 53.73% Fe, 9.02% Mn, 7.51% Al, and 2.46% Si, with a Fe recovery ratio of 88.20%, which surely meet the iron ore quality requirement of steel and iron industry.

Liquid Impact Forming (LIF) is a new composite forming technology based on Tube Hydroforming (THF) technology, which changes the volume of mould cavity through impact load and rapidly generates internal pressure to realize tube forming. It does not need external pressure supply source, and it is low cost and high efficiency. In order to study the forming characteristics of the natural bulging area of thin-walled metal tubes under different model side lengths and different model closing velocities, the change of the cavity volume of thin-walled metal tubes under impact hydraulic bulging was firstly analyzed theoretically, and a mathematical model of internal pressure was established. Then the effects of different loading parameters on the internal pressure, bulging height and wall thickness distribution in the natural bulging area of thin-walled metal tube were studied. Finally, through the comparison of finite element simulation analysis and experiment, it was found that the deviation between the experimental results and the numerical simulation was within 5%, which verified the accuracy and reliability of LIF. It also provides a certain theoretical research and application basis for the development of LIF of metal thin-walled tube.

One critical problem of metal–organic frameworks (MOFs) limiting their applications lies in the inherent instability of the frameworks constructed by the metals ions and organic ligands, which can ...

The effects of two-stage thermomechanical processing on the microstructure and properties of Cu-15Ni-8Sn-1.0Zn-0.5Al-0.2Si alloy have been investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, and mechanical and electrical property testing. Spinodal decomposition and β-Ni3Sn precipitates with L12 ordering structure appeared in the preaged alloy. The crystal orientation relationships between the copper matrix and β-Ni3Sn precipitates were (200)Cu||(100)β, [001]Cu||[001]β and ( $$ \bar{2}20 $$ )Cu||( $$ \bar{1}10 $$ )β, [112]Cu||[112]β. The high strength of the studied alloy can mainly be attributed to the combined effects of precipitation strengthening and substructure strengthening. The interaction between the nascent nanoparticles that form during pre-aging and the dislocation configurations that form during cold rolling promotes precipitation in the matrix and suppresses formation of cellular precipitates and coarse precipitates at grain boundaries, improving the comprehensive properties of the alloy. The peak-aged alloy treated with two-stage thermomechanical processing showed hardness of 387 HV, electrical conductivity of 8.5%IACS, tensile strength of 1176 MPa, yield strength of 1106 MPa, elongation of 3.86%, and strength–ductility product of 4539 MPa%.

A Cu-0.41Mg-0.06Ca (wt.%) alloy was designed and prepared by melting and casting in air atmosphere, followed by equal channel angular pressing (ECAP) process up to 12 passes via Bc route at room temperature. The microstructure and properties of the alloy were investigated by means of hardness test, tensile test, electrical conductivity measurement and electron microscopes observation. After 12 ECAP passes, the initial coarse grains were refined significantly and the average grain sizes decreased to 0.57 μm. The coarse Cu5Ca phase was also fragmented and had the sizes of about 1–3 μm. The Cu-Mg-Ca alloy after 12 ECAP passes showed excellent comprehensive properties, with a yield strength of 619 MPa, an electrical conductivity of 67.86 %IACS and a total elongation of 10.4%. Compared with the Cu-Mg alloy under the same condition, the yield strength of the designed alloy after 12 ECAP passes was improved by 30 MPa and the electrical conductivity increased by 0.63 %IACS accompanied by almost same total elongation. The good comprehensive properties were attributed to the ECAP process and the addition of Ca. The ECAP process provided much high yield strength increments which accounted for more than 80% of the yield strengths after 12 ECAP passes. In addition, the addition of Ca in the Cu-Mg alloy promoted the grain refinement, improved the work hardening ratio, and increased the electrical conductivity.

A novel Cu-1.01%Ni-0.28%Si-0.14%Co-0.45%Cr (mass percent) alloy with high strength and high conductivity was fabricated. Microstructure, mechanical and electrical properties of the alloy after multi-stage thermo-mechanical treatment were investigated in detail. The alloy has excellent comprehensive properties, with a tensile strength of 810 MPa, yield strength of 777 MPa, elongation of 3.4%, and electrical conductivity of 57.5%IACS (International Annealing Copper Standard). Three kinds of precipitates, (Cr,Co)2Si, (Ni,Co)2Si and Cr, form during aging treatment. Addition of Co element promotes the precipitation of Cr, Ni and Si solute elements from the matrix, while inhibits the growth of the (Cr,Co)2Si. The high strength of the alloy treated by multi-stage thermo-mechanical process is attributed to the dispersion strengthening, sub-structure strengthening, and work-hardening. The multi-aging process and addition of Co effectively improve the electrical conductivity of the studied alloy. The high strength and high conductivity of studied alloy make it as a potential candidate for lead frame materials in electrical and electronics industry.

Cu/SiCP composites with high strength and high conductivity were prepared by in situ carbonization reaction of silicon. The Cu-Si powder and C powder were mechanically mixed, and in situ carbonized at 850°C for 48 h, then oxidation-treated in dry air atmosphere at 650°C for 8 h, followed by reduction-treating in hydrogen atmosphere at 500°C for 90 min. The results showed that some nano-scale and micron-scale SiCp particles as well as a small amount of nano-scale SiO2 formed during fabrication. The tensile strength, yield strength, elongation and conductivity of the hot-extruded composite were 279 MPa, 180 MPa, 22.80% and 91.48% IACS, respectively; and those of the composite treated by cold-rolling with a reduction of 80% and then annealing at 350°C for 30 min were 425 MPa, 403 MPa, 10.85% and 90.15% IACS, respectively.

Adiabatic shear deformation behaviors in cold-rolled copper under different impact loading directions were systemically investigated in this paper. Split Hopkinson Pressure Bar (SHPB) system was used for the dynamic test. The microstructure and microtexture of the received shear localization regions were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and microhardness tests. Three hat-shaped specimens were cut from cold-rolled copper sheet with the direction with an angle of 0° (RD sample), 45° (RD-45° sample) and 90° (TD sample) from the rolling direction within the rolling plane. The stress-strain curves indicate that the mechanical properties of the cold-rolled copper sheet show regularity in the work hardening dominated stage and that the shear stress of TD sample is the highest in that of the those three. OM results show that the morphology of adiabatic shear band in three samples shows differences that their deformation processes fall into two categories, pure relative shearing in RD sample and relative shearing with rotation in RD-45° and TD sample. EBSD results reveal that ultrafine grains with high-angle-boundaries are found within the adiabatic shear bands in three samples. The microhardness measurements show that the microhardness of shear region in three samples are significant higher than that of other regions. However, the size of grains within the shear band in RD sample are much larger than that in the other two samples. Microtexture analysis reveals that the grain orientations inside the shear band in three samples show similar characteristics that the direction tends to parallel to the local shear direction and the {111} and {100} planes tend to parallel to the local shear plane. The calculated results show that rotational dynamic recrystallization can take place in the shear band.

Cu-0.47Cr-0.16 Nb (wt%) alloys were designed and prepared, and the microstructures of the Cu-Cr-Nb alloy were investigated using transmission electron microscopy and three-dimension atom probe tomography technique. After homogenizing at 950 °C for 4 h, cold rolling by 80% reduction, then aging at 450 °C for 30 min, the micro-hardness, electrical conductivity, tensile strength, yield strength and elongation of the alloy were up to 150 HV, 89.1%IACS, 453 MPa, 443 MPa and 11.4%, respectively. The tensile strength / elongation of the alloy approached 399 MPa / 22.9% as test at 200 ℃, 334 MPa / 14.8% for 300 ℃, and 282 MPa / 12.3% for 400 ℃, respectively. The Cr2Nb phase with an average size of 700 nm and Nb phase with an average size of 500 nm formed during the solidification process, while the nano-scale Cr-rich phases precipitated from the solid solution during the aging process. The sizes of Cr2Nb and Cr-rich phases were close to each other during aging. These precipitates located in the grain and sub-grain boundary could effectively pin the movement of boundary, resulting in a high strength of the alloy at the elevated temperature. The addition of Nb can promote the precipitation of Cr from the solid solution during aging, thus both strength and electrical conductivity of the alloy were improved.

Cu Ni Si alloys have been widely applied in electronic and electrical industries. The precipitation behavior of some of the Cu Ni Si alloys is still not well understood. In this study, the precipitation behavior of the Cu-3.0Ni-0.72Si alloy aged at 600 °C for different times was investigated by transmission electron microscopy, atom probe tomography and phenomenological theory of precipitation crystallography. A new orientation relationship (OR) between the precipitates and the Cu matrix was found in the over-aged condition and a coarsening mechanism of the metastable precipitates was put forward. The two- and three-dimension invariant line theories were successfully applied in interpreting the evolution of the ORs and the morphologies in the Cu/δ-Ni2Si (Cu/δ) system. At the early stage of aging, the fine metastable δ’-(Cu, Ni)2Si precipitates are coherent with the Cu matrix, with a quasi-Bain OR of (110)Cu||(100)δ′ and [001]Cu||[001]δ′, and four pairs of parallel conjugate planes: ( 1 ¯ 1 ¯ 1)Cu||( 3 ¯ 01)δ′, (111)Cu||(301)δ′, ( 1 ¯ 11)Cu||(021)δ′, and (1 1 ¯ 1)Cu||(0 2 ¯ 1)δ’. The precipitates have a δ-Ni2Si structure, with some Ni atoms substituted by Cu atoms. During growth, the core region of the metastable δ’-(Cu,Ni)2Si precipitate transforms into stable δ-Ni2Si, with a quasi-NW OR of ( 1 ¯ 11)Cu||(021)δ and [110]Cu||[100]δ, while a layer of metastable δ’- (Cu, Ni)2Si still exists around the core. With prolonging aging time, the δ-Ni2Si precipitates with the OR of ( 1 ¯ 11)Cu||(021)δ and [110]Cu||[100]δ grow two-dimensionally to form a plate-like shape, while those with the OR of (111)Cu||(301)δ and [ 1 ¯ 10]Cu||[010]δ grow one-dimensionally to form a fiber-like shape.

A Cu–6.0 Ni–1.0 Si–0.5 Al (wt%) alloy was fabricated, and its phase transformation behavior in the early stages of aging treatment were studied systematically, including the mechanical properties, type of precipitates, formation heat of precipitates, elastic strain energy, crystal orientation relationships, and spatial distribution of elements. The experimental results demonstrate that a B2 ordering structured β-NiAl precipitate formed in the matrix as the supersaturation solid solution (SSS) was aged at 400 °C; δ-Ni2Si, a L12 ordering structured β-Ni3Si, and L12 structured γ′-Ni3Al were precipitated from the matrix aged at 450 °C; and discontinuous δ-Ni2Si precipitates occurred in the matrix aged at 500 °C and above. Atom probe results revealed that Ni and Si formed clusters with a size of 1–2 nm, and Al tended to segregate around these clusters as the SSS was aged at 450 °C. The ultimate tensile strength of the studied alloy was 1080.2 ± 20.4 MPa for the sample aged at 450 °C for 1 h, and the electrical conductivity was 25.4% IACS. Sketch maps of the crystal orientation relationships between the matrix and precipitates were also established.

The influence of 60Co gamma-ray irradiation on the chemical compositions and properties of an epoxy encapsulant was investigated. The total irradiation dose varied from 0.1 kGy to 100 kGy with a fixed dose rate of 500 Gy/h. Fourier transform infrared spectra, X-ray photoelectron spectroscopy analysis and discoloration proved the occurrence of oxidation caused by the irradiation. Tg and density remained unchanged owing to the competing effects of irradiation-induced degradation and crosslinking. The tensile strength, impact strength and electrical strength did not decrease distinctly until the irradiation dose reached above 11 kGy. Rubbery coefficient of linear thermal expansion (CTE), relative permittivity and dissipation factor, on the contrary, were more sensitive to the oxidation and increased sharply when the irradiation dose was only 0.1 kGy. Our results suggested that the evolution of CTEs and dielectric properties could affect the long-term application and reliability of the epoxy encapsulant in the irradiative environment.

The Cu–4.5Ni–1.2Co–1.0Si–0.15Mg alloy with super-high strength and high electrical conductivity was designed, and a two-step thermo-mechanical treatment was applied to improve the mechanical and electrical properties of the alloy. The microstructure and properties of the alloy were investigated by transmission electron microscope observation, tensile test, hardness and electrical conductivity measurements. The results show that the final alloy treated by two-step thermo-mechanical process has a hardness of 329 HV, a yield strength of 1086 MPa, an elongation of 3.6%, and an electrical conductivity of 30.1%IACS, respectively. The nanoscale β-Ni3Si and δ-(Co,Ni)2Si precipitates form during the thermo-mechanical process, and the addition of the Co could promote the precipitation of δ-(Co,Ni)2Si particles. The orientation relationship (OR) between Cu matrix and the precipitates is: (022)Cu//(011)β//(010)δ and [100]Cu//[100]β//[001]δ. Comparing with the directly aging treatment and one step thermo-mechanical treatment, precipitates that form during the two-step thermo-mechanical process are much smaller and distributed more densely, resulting in the better comprehensive properties of the alloy.

NO catalytic oxidation (NOCO) to NO2 is widely believed to be a fundamental step in selective catalytic reduction (SCR) over activated carbon (AC). Thus, the enhancement of NOCO over AC is significant. The effect of the pore structure on NOCO is discussed first. A series of microporous AC samples with various microporous surface areas were prepared, in which a strong positive correlation existed between NO conversion and the microporous surface area. With an increase in the microporous surface area, the NO conversion increased from 13.10% for MAC1 to 41.18% for MAC4. Concurrently, a hierarchical AC sample with an approximate hierarchy degree (the ratio of Vmes+mac to Vt) of 50% demonstrated higher NO conversion than microporous AC when the microporous surface areas were similar. HAC2 exhibited the largest NO conversion (51.58%). Therefore, the microporous surface area and degree of hierarchy are key factors that enhance NO conversion. NOCO has been demonstrated to be an O-enriched process. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) results revealed that carbonyl groups were generated during the NOCO process. Density functional theory calculations were then performed. Carbonaceous models with unsaturated C atom, carbonyl, and lactone groups were constructed, and the corresponding NOCO reaction paths were calculated. A dual-site NOCO mechanism was proposed by combining the experimental and calculation results. Two types of active sites existed: unsaturated C atoms and high-spin density C atoms that affected the kinetic and steady-state stages of NOCO, respectively. The total amount of high-spin density C atoms strongly depends on the microporous surface area. The study of NOCO was updated, which contributed to the preparation of highly efficient AC for NOCO.

The microstructural evolutions and properties variations of a CuCrZrY alloy processed by equal channel angular pressing (ECAP) with different passes were studied systematically. After 4 passes of ECAP, the average grain size was decreased to 500 nm, and the grain size distribution became more uniform during the subsequent processing. After 8 passes ECAP-ed and aged at 400 °C for 7 h, the samples’ tensile strength and electrical conductivity are 560 MPa and 86.4%IACS. The main strengthening mechanisms are precipitation strengthening, low-angle grain boundary strengthening, and high-angle grain boundary strengthening (about 82% in total). Finite element simulation was carried out through ABAQUS to obtain the equivalent strain distribution diagram of ECAP, resulting in that the strain force of the outer region was less than that of the inner one. The inconsistency of deformation leads to the inhomogeneity of microstructure. These findings will effectively guide researchers to develop high-strength high-electrical conductivity copper alloys.

In the continuous pickling line, the acid temperature setup accuracy was low, which not only caused excessive pickling defects, but also caused excessive consumption of hydrochloric acid and a decrease in pickling efficiency. In order to solve this problem, the acid temperature setup model based on case-based reasoning (CBR) technology was established by using a large amount of production data with good temperature setting precision. After the model was put into operation on a 1450mm pickling and rolling line, the average pickling defect ratio decreased from 14.99904% to 11.7332% and the fluctuation range of the pickling defect ratio was effectively controlled. Practical application showed that the setup accuracy of the acid temperature model was effectively improved. As the number of strip steel production increases, the model has the adaptive ability to change with the working conditions, which is suitable for industrial promotion.

Detection and manipulation of spin current lie in the core of spintronics. Here we report an active control of a net spin Hall angle, θSHE(net), in Pt at an interface with a ferroelectric material PZT (PbZr0.2Ti0.8O3), using its ferroelectric polarization. The spin Hall angle in the ultra-thin Pt layer is measured using the inverse spin Hall effect with a pulsed tunneling current from a ferromagnetic La0.67Sr0.33MnO3 electrode. The effect of the ferroelectric polarization on θSHE(net) is enhanced when the thickness of the Pt layer is reduced. When the Pt layer is thinner than 6 nm, switching the ferroelectric polarization even changes the sign of θSHE(net). This is attributed to the reversed polarity of the spin Hall angle in the 1st-layer Pt at the PZT/Pt interface when the ferroelectric polarization is inverted, as supported by the first-principles calculations. These findings suggest a route for designing future energy efficient spin-orbitronic devices using ferroelectric control., The spin Hall angle (SHA) is a measure of the efficiency for converting a charge to a spin current is still challenging to tune in situ. Here, the authors demonstrate by introducing a ferroelectric (FE) material in a ferromagnetic/heavy metal stack the SHA can be voltage controled via the polarization of the FE layer.

A thin-disk multipass amplifier with good stability for the thermal lensing of disk is presented. Simulations and experiments demonstrated slight beam variations on the disk of which the dioptric power varies in a wide range.

The quench sensitivity of AA7N01 aluminum alloy used for high-speed train body structure was investigated by end-quenching test, time–temperature-transformation curves simulation, transmission electron microscopy and scanning transmission electron microscopy. The hardness decreased with the increasing distance from the quenched end, and the depth of the age hardening layer was about 50 mm. The simulation results showed that the high quench sensitivity temperature was between 230°C and 300°C and the critical cooling rate should be larger than 2°C/s. The decrease of hardness along the increasing distance from the quenched end was attributed to the coarsening of the η equilibrium phase and the widening of the precipitate-free zone. The high-angle annular dark field results provided the direct evidence of the induced-precipitation effect of Al3Zr particles during the quenching process.

High temperature response capability is critical for multifunctional carbon nanotube polymer nanocomposites. In this work, a CNT/polymer nanocomposite with high temperature coefficients of resistance (Average value = −3%/K, Peak value = −7%/K, Response range = 323 K–473 K) was fabricated successfully. By developing a percolation network model, this work reveals theoretically that the observed high temperature response is mainly resulted from glass transition of polymer matrix. During this process, the electron transport at CNT junctions switched from quantum tunneling to thermally activated hopping. The simulation results also reveal that the temperature response capability can be further improved (Average value = −4.7%/K, Peak value = −10%/K, Response range = 380 K–500 K) by using Polytetrafluoroethylene as polymer matrix with 0.5 wt% CNT loadings. These highly sensitive, low cost composites have a great potential for wide range applications, such as temperature sensors and temperature threshold switches.

Temperature-independent property and high piezoresistivity are critical for carbon nanotube polymer nanocomposites with sensing capability. In this work, a temperature-independent CNT/Epoxy resin nanocomposite was fabricated successfully. This composite has good and stable piezoresistivity between 233 K and 373 K. By developing a multi-scale percolation network model, this work also reveals theoretically the inherent mechanisms to obtain temperature-independent sensors. In order to fully consider the tube–tube and/or tube–matrix interaction in the composite, the structural distortion of nanotubes is determined self-consistently by minimizing the pseudo-potential energy and the thermally assisted tunneling transport is calculated by the Landauer-Buttiker formula. Simulation results show that temperature-independent composite with further improved piezoresistivity (gauge factor > 40) can be achieved by dispersing the treated and selected CNTs to the theoretically matched polymer matrix. These temperature-independent, highly sensitive, low cost and homogeneous sensors have a great potential for wide range applications, such as in electronic skin, man-machine interaction and body monitoring.

Magnesium was added into Cu-Cr alloy to overcome the traditional limitations of high-cost and large-scale manufacturing of Cu-Cr alloys and to unveil the acting mechanism of Mg on the microstructure and properties of Cu-Cr alloy. Effect of magnesium on microstructure and properties of Cu-Cr alloy has been investigated by means of hardness test, electrical conductivity measurement, transmission electron microscopy, three-dimension atom probe tomography technique and X-ray diffraction analysis. The precipitation sequence of Cu-Cr-Mg alloy was similar with that of binary Cu-Cr alloy. Additional magnesium in Cu-Cr alloy accelerated the process of precipitates nucleation, restrained the growth of the precipitates by segregating along precipitates surface during aging. This enhanced the stability of the deformation microstructure and improved the mechanical properties of the alloy. Cu-Cr-Mg alloy showed a better comprehensive properties and softening resistance performance than Cu-Cr alloy at elevated temperature. After aged at 480 °C, Cu-Cr-Mg alloy had a tensile strength of 540 MPa and an electrical conductivity of 79.2 %IACS for the peak aging states, and it still maintained a tensile strength of 515 MPa and an electrical conductivity of 80.8 %IACS after 4 h aging.

There is a challenging trade-off between the high strength and high electrical conductivity in copper-based alloys. Designed Cu-3.65 wt%Nb (CN) and Cu-3.48 wt%Nb-0.11 wt%Si (CNS) alloys were fabricated by vacuum melting and followed by thermal-mechanical treatment. Microstructure evolutions and properties measurements were studied. Results indicate that morphologies of the Nb3Si phase in the CNS alloy are solid or hollow regular polygons whose boundaries are parallel to one of Nb3Si's crystal faces. The Nb3Si's precipitation can effectively improve the strength, while the Nb3Si tip is easy to form stress concentration, which leads to crack and failure. The high electrical conductivity of the CNS alloy was because of the decomposition precipitation of Nb and Nb3Si during aging treatment. After hot-rolled by 80% at 900 °C, cold-rolled with a strain of 2.30, the ultimate tensile strength of CN and CNS alloys were 488 MPa and 510 MPa, electrical conductivities were 88.06%IACS (International Annealed Copper Standard) and 93.20%IACS, and elongation rates were 9.3% and 7.1%, respectively. These findings reported a new method to fabricate high-strength and high-conductivity copper alloy.

This study aims to enhance the dimensional stability of alumina dispersion strength copper alloy via creep annealing treatment. The microstructure, residual stress and micro-yield strength of alloys after different treatments were investigated. During creep annealing, the residual stress in the alloy was dramatically reduced due to the decrease of dislocation density. The nano-Al2O3 particles in the alloy did not coarsen or agglomerate during the high temperature treatment and retarded the growth of subgrains effectively, which played important roles in high micro-yield strength of creep annealed alloy. The pores were effectively reduced by the creep deformation during creep annealing, resulting in a more uniform residual stress distribution and an increase in micro-yield strength. Compared with extruded alloy, the residual stress of alloy creep annealed at 950 °C for 12 h was reduced by 88%, while the micro-yield strength increased by 9.7%, leading to a significant enhancement in dimensional stability of the alloy.

A Φ40 μm Cu-4 wt%Ag alloy wire with high strength and high electrical conductivity was prepared by continuously directional solidification and cold drawing. The evolution of microstructure and properties was investigated by means of optical microscope observation, electron microscopes observation, hardness test, tensile test, and electrical conductivity measurement. The continuous columnar-grain structure uniformly distributed along the solidification direction in the as-cast alloy. The drawing process was divided into three stages: general deformation stage, large deformation stage and extreme deformation stage. The main deformation mechanisms of the alloy in each stage are corresponding to the dislocation slip and twinning, the dynamic recovery, the evolution of layered interface, and partial dynamic recrystallization. After the deformation with the drawing strain of 11.28, the tensile strength, yield strength, and electrical conductivity of the alloys were 1048 MPa, 886 MPa, and 75.2%IACS, respectively. The main strengthening mechanism of the alloys was grain refinement strengthening according to the calculation results of the strengthening model.

The contact wires in high-speed railway industry should have high strength, high electrical conductivity, and high industrial manufacturing feasibility. An economical Cu-0.29Mg-0.21Ca (wt.%) alloy has been designed and synthesized by non-vacuum melting and casting followed by thermal-mechanical treatments. Microstructure evolutions and mechanical properties of the studied alloy were investigated systematically. Microstructure observations showed that after cold deformation, the initial grain size was significantly refined into small grains full of sub-structures with an average size of 400 nm. After homogenized at 780 °C for 1 h, followed by cold rolling reduction of 80%, then annealed at 200 °C for 1 h, properties measurements revealed that the studied alloy had outstanding comprehensive performance with an ultimate tensile strength of 545 MPa, a yield strength of 526 MPa, an elongation of 3.60%, and an electrical conductivity of 71.79%IACS. The high electrical conductivity was due to the addition of Ca which purified the copper matrix through reacting with some impurity elements and caused little electron scattering. The high strength was attributed to the dispersion strengthening, solid solution strengthening, sub-structure strengthening, and dislocation strengthening, in which sub-structure strengthening is dominate.

The effect of Si on the microstructure and properties of Cu–10Fe alloy was systematically studied in this paper. By adding 0.4 wt% Si to Cu–10Fe alloy, the mechanical properties, electric conductivity, thermal conductivity, saturation magnetization and electromagnetic interference shielding effectiveness are significantly improved. After 90% cold rolling and 450 °C/32 h heat treatment, the electrical conductivity, thermal conductivity, tensile strength, elongation and electromagnetic interference shielding effectiveness of Cu–10Fe-0.4Si alloy are 68.02 %IACS, 304 W/(m·K), 521 MPa, 29.6% and 107.4 dB, respectively. Microstructure observation shown that FCC FeSi phases formed in two different sizes and the precipitation of the Fe atoms was promoted in Cu–10Fe-0.4Si alloy, which lead to the simultaneously improvement of conductivity, strength and magnetic properties. This high-strength, high-conductivity and magnetic Cu–Fe alloy has great application potential in electromagnetic shielding and other fields.

Currently, the simultaneous and directional regulation of specific surface area (SBET) and pore hierarchy (the percentage of mesoporous and macroporous volume to total pore volume, Vmes+mac/Vt) of activated carbon (AC) lacks a systematic preparation mechanism. In this study, AC samples were prepared from coconut husks, and the effect of carbonization methods, activation methods, and process parameters on the development of the pore structure were explored. N2 adsorption–desorption results indicated that AC samples prepared via conventional carbonization were microporous. Hierarchical AC samples were obtained by the combination of hydrothermal carbonization at 240 °C and physical activation. CaCl2 impregnation was found to be beneficial to the preparation of meso-/macroporous AC samples. Based on these results, a series of AC samples with typically varied pore hierarchies (18.05–76.73 %) with similar specific surface areas (∼450.0 m2 g−1) were obtained. AC samples with similar pore hierarchies and different specific surface areas were also prepared, including microporous AC (SBET: 330.5–761.4 m2 g−1; Vmes+mac/Vt: 12.21–14.06 %), hierarchical AC (SBET: 445.9–780.7 m2 g−1; Vmes+mac/Vt: 51.04–54.89 %), and meso-/macroporous AC samples (SBET: 371.1–516.0 m2 g−1; Vmes+mac/Vt: 67.39–75.25 %). A systematic preparation mechanism for the directional regulation of the pore structure of AC is proposed, which is significant for the preparation of high-efficiency AC for different applications.

Modern electronics components require copper alloys to have higher strength and ductility for processing and forming. Cu–Ti alloys exhibit excellent mechanical properties while their plasticity is limited. In this work, high ductility Cu–Ti alloys were fabricated and investigated systematically, results indicated that the samples' strength and plasticity can be improved by adding high Ti and Cr content. The crystal relationship between the β′-Cu4Ti and Cu is that: [100] Cu//[011] β'-Cu4Ti, (020) Cu//(2 1 ‾ 1) β'-Cu4Ti. Further increase aging time, metastable β′-Cu4Ti particles started cellular reaction to be β-Cu3Ti phase, which were detected at the grain boundary. The crystal relationship between the β-Cu3Ti and Cu is that: [100] Cu//[011] β-Cu3Ti, (220) Cu//(400) β-Cu3Ti. The hardness, yield strength, elongation of the CuTiCrMg alloy after aging at 450°C for 30 min are 394 HV, 1057 MPa, and 1.6%, respectively. While, those of the CuTiCrMg–Fe alloy are 370 HV, 1160 MPa, and 10%, respectively. The precipitation strengthening is the primary strengthening mechanism. These findings are of great significance for developing Cu–Ti alloys with high strength and high plasticity.