Effects of operating parameters in the thermal gradient chemical vapor infiltration of propane such as thermal gradient, diffusion, infiltrations time, and concentration of propane were studied by focusing on the visualizations of the intrinsic effects of these parameters. A uniform deposition in the preform was obtained with a gradually increasing temperature along the gas flow. The uniformity of deposition through the preform got improved with increasing deposition time. Results of numerical modeling estimated the experimental data very well when the pre-exponential factor of the overall rate of carbon deposition from propane reported by Vaidyaraman^[1] was multiplied by 4. The average density of a preform increased by about 3 times from 0.38 to 1.15 g/cm³ after 60 hr deposition with a thermal gradient under the conditions of 3% propane in nitrogen and 840 to 900 °C.

The results of a study on the homogeneity of suspensions are described considering the effect of different types of surfactant stabilizers and their concentrations on the uniform distribution of a carbon nanotubes (CNTs)-based modifying additive to construction materials in an aqueous medium. This problem was solved herein by using surfactants and ultrasound. The sonication treatment of CNTs particle agglomerates allowed for dispersing their globules and achieving a 15-20-fold decrease in their average size, for which it became possible to make better use of the CNTs as cement modifier. As a result of the experimental studies carried out, the effect of the surfactant type and concentration promoting uniform distribution of the CNTs in the bulk of the suspension and, correspondingly, in the structural composite matrix was revealed. The CNTs-based additive improved the physical-mechanical and operational characteristics of the material.

A novel method to prepare an electrocatalyst with a new structure and high catalytic performance was reported. Two-dimensional (2D) PtRu nanoclusters have been successfully deposited on graphene oxide and carbon black supports. Compared with the commercial 3D E-TEK PtRu samples, the prepared 2D PtRu composites have larger electrochemically active surface area and display much higher catalytic activity toward methanol oxidation reaction. The preparation method mainly includes the following procedures: oxidation of carbon matrix, Pb²⁺ adsorption on the surface of carbon support, Pb²⁺ electrochemical reduction and galvanic displacement of Pb⁰ by Pt²⁺ and Ru³⁺. The method developed in this study could be viable for solving the problem of low electrocatalytic activity in direct methanol fuel cell anodes.

X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructure and morphology of Au NPs/ZnO NTs, and their photo-catalytic capability was assessed to a nicety. The results demonstrated that the diameter and the wall thickness of ZnO nanotube were about 200 and 50 nm, respectively. The diameter of Au nanoparticle was about 30 nm. The characterization on the photo-catalytic capability of the Au-ZnO nanotube hybrid indicated that the degradation of methyl orange was 80% within 4 h. Controlled experiments have shown that Au-ZnO nanotube hybrid presents superior photo-catalytic capability to both bare ZnO nanorod and Au-ZnO nanorod hybrid indicated that the degradation procedure of methyl orange.

(Ba_0.6Sr_0.4)_0.85Bi_0.1TiO₃ ceramics doped with x wt%CaZrO₃ (x= 0-10) were synthesized by solid-state reaction method. The effects of CaZrO₃ amount on the dielectric properties and structure of (Ba_0.6Sr_0.4)_0.85Bi_0.1TiO₃ ceramics were investigated. X-ray diffraction results indicated a pure cubic perovskite structure for all samples and that the lattice parameter increased till x=5 and then slightly decreased. A homogenous microstructure was observed with the addition of CaZrO₃. Dielectric measurements revealed a relaxor-like characteristic for all samples and that the diffusivity γ reached the maximum value of 1.78 at x=5. With the addition of CaZrO₃, the dielectric constant dependence on electric field was weakened, insulation resistivity enhanced and dielectric breakdown strength improved obviously and reached 19.9 kV/mm at x=7.5. In virtue of low dielectric loss (tan δ<0.001 5), moderate dielectric constant (ε _r >1 500) and high breakdown strength (E _b >17.5 kV/mm), the CaZrO₃ doped (Ba_0.6Sr_0.4)_0.85Bi_0.1TiO₃ ceramic is a potential candidate material for high power electric applications.

Alpha nickel hydroxide has better performances than commercial beta nickel hydroxide. However, the main defect is that α-phase is difficult to synthesize and easily transformed to β-phase Ni(OH)₂ upon aging in a strong alkaline solution. In this study, the Al-Co, Al-Yb, Yb-Co and Al-Yb-Co multiple doping was used respectively. By controlling the amount of sodium carbonate, the α-Ni(OH)₂ was prepared by ultrasonic-assisted precipitation. And the influence of sodium carbonate on the crystalline phase and structure stability for alpha nickel hydroxide was studied. The results demonstrate that, with increasing amount, the biphase nickel hydroxide transforms to pure alpha nickel hydroxide gradually, and the structure stability is also improved. When the amount of sodium carbonate is 2 g, the sample still keeps α-Ni(OH)₂ after being aged for 30 days, for Al-Yb-Co-Ni(OH)₂. And when the amount is less than 2 g, the phase transformations exist in the samples with different extents. These results demonstrated that the amount of sodium carbonate is a critical factor to maintain the structural stability of α-Ni(OH)₂.

A facile approach has been developed to synthesize Fe₃O₄@PAM (polyacrylamide) nanoparticles (NPs) with carboxyl groups on the surfaces by copolymerization with acrylamide and acrylic acid in Fe₃O₄ NPs aqueous suspension. Nitrilotriacetic acid (NTA) was conjugated to the magnetic NPs via well-known carboniimide chemistry using EDC and NHS. The Ni²⁺ ions loaded on the surface of NPs provide abundant docking sites for immobilization of His-tagged green fluorescent proteins (His-tagged GFP). The high magnetic property of Fe₃O₄@PAM@NTA-Ni²⁺ allows an easy separation of the NPs from solution under an external magnetic field, with high His-tagged protein binding capacity (42 μg protein/mg of NPs). The NPs can be recycled for at least four times without significant loss of binding capacity to proteins. These materials show great potential to separate His-tagged protein with low-cost purification at industrial scale.

The spontaneous magnetic transitions and corresponding magnetoelastic properties of intermetallic compounds RMn₂Ge₂ (R=Gd, Tb and Dy) were investigated by using the X-ray diffraction method and magnetic measurement. The results showed that the compounds experience two magnetic transitions, namely the second-order paramagnetic to antiferromagnetic transition at temperature T _N (T _N=368, 423 and 443 K for GdMn₂Ge₂, TbMn₂Ge₂ and DyMn₂Ge₂, respectively) and the first-order antiferromagnetic - ferrimagnetic transition at temperature T _t (T _t=96, 80 and 40 K for GdMn₂Ge₂, TbMn₂Ge₂ and DyMn₂Ge₂, respectively) as the temperature decreases. The temperature dependence of the lattice constant a(T) displays a negative magnetoelastic anomaly at the second-order transition point T _N and, at the first-order transition T _t, a increases abruptly for GdMn₂Ge₂ and TbMn₂Ge₂, Δa/a about 10^-3. Nevertheless, the lattice constant c almost does not change at these transition points indicating that such magnetoelastic anomalies are mainly contributed by the Mn-sublattice. The transitions of the magnetoelastic properties are also evidenced on the temperature dependence of magnetic susceptibility χ. The first-order transition behavior at T _t is explained by the Kittel mode of exchange inversion.

The electron paramagnetic resonance (EPR) spectra of trigonal Mn²⁺ centers in Zn(ClO₄)₂·6(H₂O) and Mg(ClO₄)₂·6(H₂O) crystals were studied on the basis of the complete energy matrices for a d ⁵ configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn²⁺ center has an compressed distortion along the crystalline c ₃ axis, and when Mn²⁺ is doped in the Zn(ClO₄)₂·6(H₂O) and Mg(ClO₄)₂·6(H₂O) crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 Å, for Zn(ClO₄)₂·6(H₂O), R=2.130 2 Å, for Mg(ClO₄)₂·6(H₂O) have been determined.

Titania (TiO₂) nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride (TiCl₄) as titanium source, methylene dichloride (CH₂Cl₂) as solvent, absolute ethyl alcohol (CH₃CH₂OH) as oxygen donor. The effects of Si⁴⁺ doping on the TiO₂ nanocrystalline phase transformation temperature were systematically researched. The results showed that when the molar ratio of Ti⁴⁺ to Si⁴⁺ is 1 to1.3, TiO₂ prepared by calcination at 1100 °C for 1 hour exhibits rod shape and has good photocatalytic activity. Doping of Si⁴⁺ makes glass phase core-shell structure forming on the surface of anatase crystal particles, which can inhibit crystal phase transformation and raise the transformation temperature, making TiO₂ stable in anatase phase at 1200 °C.

A diamond-like carbon (DLC) film was deposited on YT14 substrate using magnetron sputtering (MS). The surface morphologies, roughness and bonding spectra of obtained film were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS), respectively, and its mechanical property and bonding strength were measured using a nanoindentation and scratch tester, respectively. The results show that the C-enriched DLC film exhibits a denser microstructure and smoother surface with lower surface roughness of 21.8 nm. The ratio of C sp2 at 284.4 eV that corresponds to the diamond (111) and the C sp3 at 285.3 eV that corresponds to the diamond (220) plane for the as-received film is 0.36: 0.64, showing that the C sp3 has the high content. The hardness and Young’s modulus of DLC film by nanoindentation are 8.534 41 and 142.158 1 GPa, respectively, and the corresponding bonding strength is 74.55N by scratch test.

Plasma-enhanced CVD (PECVD) epitaxy at 200 °C was used to deposit heavy doped n-type silicon films. Post-annealing by rapid thermal processing was applied to improve the properties of the epitaxial layer. By analyzing the Raman spectra and the imaginary part of the dielectric constant spectra of the samples, it was found that high-quality heavy-doped epitaxial n-type silicon layer can be obtained by optimizing the parameters of the PECVD depositing process. Reducing the electrodes distance of the PECVD had a great effect on the crystallzation of the epitaxialed n-type silicon films. Sillicon films with high-crystallization were obtained with the electrodes distance of 18 mm. Post-annealing process can improve the crystallization and reduce the resistance of the epitaxial films. In our research, it was found that the sheet resistance (R _□) of the post-annealed films with thickness of about 50 nm has a simple relationship with R _PH3/SiH4 (ratio of the flow rate of PH₃ and SiH₄) of the PECVD processing: R _□=-184-125 lg(RPH₃/SiH₄). In the end, high-quality epitaxial n-type silicon film was obtained with R _□ of 15 Ω/□ and thickness of ~50 nm.

The fundamental characteristics of varied initial core-sizes of BaTiO₃(BT) and its influential role on the morphology and dielectric properties of BaTiO₃@0.6BaTiO₃-0.4BiAlO₃(BT@0.6BT-0.4BA) ceramic samples were studied. Alkoxide sol-precipitation method was adopted as revised chemical route to synthesize the constituent “core” BT powders in a dispersed phase, whereas the distinctive initial nano-sized particles were affected by the pre-calcination temperatures (600-900 °C).The microstructure of the uncoated BT ceramics revealed an exaggerated grain growth with an optimized dielectric constant (ε _max >9 000) whilst the coated ceramics behaved otherwise (grain growth inhibited) when sintered at an elevated temperature. Regardless of the previously studied solubility limit (about 0.1%) of BT-BA samples, BT@0.6BT-0.4BA maintained a maximum dielectric constant (ε _max) ranging from 1 592 to 1 708 and tan δ less than 2% under a unit mole ratio at room temperature. In view of all these analyses, the initial nanometer sizes of the as-prepared BT-core powders combined with the increase effect of cation substitutions of Bi³⁺ and Al³⁺ in the shell content, induced the diffuse transition phase of BT@0.6BT-0.4BA composition.

To efficiently utilize the kaolin, an economical way of preparing cordierite ceramic with high performance for electric heater supports was put forward. In this study, sintering process, phase transformation, microstructure evolutions were systematically studied by heating microscope, X-ray diffraction, scanning electronic microscope and thermal analysis. Properties (physical properties, electrical properties and coefficient of thermal expansion (CTE)) were tested for comprehensive performance evaluation. The results showed that the utilization of poor quality kaolin broadened the firing range of cordierite ceramic which was from 1 200 to 1 380 °C. Microstructure becomes loose with increasing of the pore size, which had significant influence on bending strength and electrical properties. High content of K₂O in poor quality kaolin was the reason for liquid phase generation in sintering process, which further leads to microstructural changes. The cordierite ceramic sintered at 1 320 °C had the properties as follows: CTE of 1.98×10^-6 °C^-1 (500 °C), bending strength of 90 MPa, apparent porosity of 15.1%, dielectric constant of 7.5 (100 Hz), and volume resistivity of 1.05×10⁹ Ω·cm (100 Hz). The comprehensive properties are very suitable for use as electric heater supports.

This work focuses on the dynamic rheological behavior of low water-to-binder ratio cement mortars blended with fly ash microspheres (FAM) or silica fume (SF). The initial slump flow of each group has been controlled at similar values by adjusting the superplasticizer dosages. With the help of a coaxial cylinder rheometer, the dynamic rheological behaviors of these mortars are investigated by frequency sweeping in the range of 0–2 Hz under large amplitude oscillatory shear (LAOS). Based on the systematical elaboration of dynamic rheological testing theory, the experimental data are processed according to Lissajous plot fitting to reveal the viscoelastic characteristics. The nonlinearity of response signals is further assessed with Fourier transform (FT) analysis. The parameters, storage modulus G', loss modulus G" and relative amplitude I ₃/I ₁ are proposed to clarify the influences of FAM and SF on the stability and energy consumption of local structures and nonlinearity of response torques. The hydration characteristics of various groups well confirmed the rheological phenomenon. This study is beneficial for the preparation and optimization of flow state concrete such as pumping concrete and self-compacting concrete.

Calcium silicate hydrate (C-S-H) with Ca/Si ratio 1.0 was prepared via precipitation in solution and heated at various temperatures to investigate its dehydration behavior. The dehydration, structural collapse and recrystallization characteristics of C-S-H and its microstructural change during heating process were investigated by XRD, SEM, Raman and TG-DSC techniques. C-S-H gradually lost non-evaporable water upon heating, about 50% and 80% non-evaporable water was removed below 200 and 400 °C, respectively, and the rest was removed up to about 1 000 °C. At 400 °C, dehydrated C-S-H exhibited the increasing disordering of calcium/silicon environment and the decreasing symmetrical bending vibration of Si-O-Si of Q ² silicate chains. At 650 °C non-bridging oxygen atoms (O_non) attached to silicon were almost removed, and significant structural change occurred, and at 815 °C C-S-H dehydrated to wollastonite.

The phosphorus slag (PS) can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wetmilling (reducing d ₅₀ to as low as 2.02 μm) in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early- and late-stage strengths, are significantly mitigated. When d ₅₀=2.02 μm, the slurry becomes strongly alkaline (pH=12.16) compared to the initial d ₅₀=20.75 μm (pH=9.49), and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.

LDHs was introduced into 70# asphalt binder by different weight ratio. Asphalt penetration test, soft point test, ductility test, viscosity test, dynamic shear rheometer (DSR) test and Fourier transform infrared (FTIR) test, were conducted to characterize and predict the LDHs modified asphalt. Research results indicated that the LDHs has great effect on resistance to UV of asphalt, which makes the asphalt absorb less ultraviolet radiation under the same UV intensity. Complex modulus, phase angle and FTIR test results indicate that the LDHs can significantly enhance the property of anti-ultraviolet aging of asphalt. The test results show that the LDHs has an obvious improvement on the anti UV aging of asphalt.

The microstructural evolution of C-(A)-S-H gel in Portland cement pastes immersed in pure water and 5.0 wt% Na₂SO₄ solution for different ages was comparatively investigated, by means of ²⁹Si NMR spectroscopy, and SEM-EDS analysis. Additionally, molecular dynamics simulation was performed to study the aluminum coordination status and interaction of sulfate ions in C-(A)-S-H gel. The results showed significant changes in the microstructural evolution of C-(A)-S-H gel in Portland cement paste. Sulfate attack has decalcifying and dealuminizing effect on C-(A)-S-H gel which is evident from increase in mean chain length (MCL) and decrease in Ca/Si & Al[4]/Si ratios of C-(A)-S-H gel. Additionally, Molecular dynamics simulation proves that Al[4] substituted in silicate chains of C-(A)-S-H gel is thermodynamically metastable, which may explain its migration from the silicate chains and transformation to Al[6], thus lowering the Al[4]/Si ratio of C-(A)-S-H gel. SO₄ ^2- ions can carry the interfacial Ca²⁺ ions into the pore solution by the diffusion-absorption-desorption process, which unravels the mechanism of sulfate attack on C-(A)-S-H gel.

The effect of carbonation treatment and mixing method on the mechanical properties and interfacial transition zone (ITZ) properties of recycled aggregate concrete (RAC) was investigated. Properties of recycled concrete aggregate (RCA) were tested firstly. Then, five types of concretes were made and slump of fresh concrete was measured immediately after mixing. Compressive strength and splitting tensile strength of hardened concrete were measured at 28 d. Meanwhile, the microstructure of RAC was analyzed by backscattered electron (BSE) image. It was found that the water absorption ratio of carbonated recycled concrete aggregate (CRCA) was much lower when compared to the untreated RCA. Comparatively, the apparent density of CRCA was not significantly modified. The concrete strength results indicate that the mix CRAC-2 prepared with CRCA by adopting two-stage mixing approach shows the highest compressive strength value compared to the other mixes. The microstructural analysis demonstrate that the mix CRAC-2 has a much denser old ITZ than the untreated RAC because of the chemical reaction between CO₂ and the hydration products of RCA. This study confirms that the ITZ microstructure of RAC can be efficiently modified by carbonation treatment of RCA and encourages broadening the application of construction and demolition wastes.

Early hydration mechanism of cement-based materials with silica fume, nano-SiO₂ and silica sol of different contents was investigated, and the detailed effect of these Si-rich mineral admixtures in three stages of early hydration (NG, I, D) using kinetics model was focused. The results showed that silica fume, nano-SiO₂, and silica sol have significant effect on kinetic parameters n, k ₁, k ₂ and k ₃, the fineness and existing form of SiO₂ particles in these Si-rich mineral admixtures are two important factors to affect the hydration process and on the parameters. Through integrated use of methods of hydration heat-Krstulovic-Dabic Modelsynthetical thermal analysis, data of hydration heat were collected, hydration degree was characterized, as well as the resulting crystallization behavior of early hydration, to build a numerical relationship between parameter n and CH contents that n decreases with increasing CH, and thus, a direct connection between hydration heat release behavior and crystallization behavior has been established.

Lignin as the main component of black liquor is generally employed to modify aliphatic superplasticizer (AFS). However, the modification effect is hard to evaluate correctly due to the uncertain molecular structure of lignin and the disturbance from the complexity of black liquor compositions. In this paper, the purified lignin via acid precipitation from straw black liquor is used to modify AFS. The modified AFS named as LAFS for short presents lower molecular mass than AFS. It is assumed that it is due to the single active site of guaiacol segments in lignin by which lignin graft modifies AFS in virtue of methylolation reaction. In order to verify this assumption, guaiacol and dihydro eugenol as the typical segments of lignin macromolecule were selected, respectively, as the simplified model compounds of lignin to modify AFS, and corresponding products are abbreviated in GAFS and DAFS. Both GAFS and DAFS show the lower molecular mass than unmodified AFS. FTIR and TG-DTG analyses prove that lignin is successfully grafted onto AFS. The graft modification of lignin results in a decrease in electrostatic epulsion, but an enhanced steric hindrance. Therefore, although the replacement rate of lignin in LAFS was about 23.3%, the dispersion performance was only slightly affected.

The hardfacing alloys with different concentrations of titanium were deposited on carbon steel substrates by shielded metal arc welding, and the effect of titanium content on the microstructure characteristics of the hardfacing alloys was investigated. The wear resistance test of the hardfacing alloys was carried out by using a slurry rubber wheel abrasion test machine, and the wear behaviour was also studied. The results indicate that the addition of titanium can effectively promote the precipitation of the complex carbides of Nb and Ti due to the prior precipitation of titanium carbide which acts as nucleation sites for complex carbides. With the increase of titanium content, the wear resistance of the hardfacing alloys is increased gradually resulting from the refinement of microstructure and dispersive distribution of fine carbide precipitates. And the wear mechanism is mainly minimum plastic deformation with interrupted grooves due to the strengthening and protecting effects of carbide precipitates.

For TA15 titanium alloy, slip is the dominant plastic deformation mechanism because of relatively high Al content. In order to reveal the grain-scale stress field and geometrically necessary dislocation (GND) density distribution around the slip traces and phase boundaries where the slip lines are blocked due to Burgers orientation relationship (OR) missing. We experimentally investigated tensile deformation on TA15 titanium alloy up to 2.0% strain at room temperature. The slip traces were observed and identified using high resolution scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) measurements. The grain-scale stress fields around the slip traces and phase boundaries were calculated by the cross-correlationbased method. Based on strain gradient theories, the density of GND was calculated and analyzed. The results indicate that the grain-scale stress is significantly concentrated at phase/grain boundaries and slip traces. Although there is an obvious GND accumulation in the vicinity of phase and subgrain boundaries, no GND density accumulation appears near the slip traces.

The combined effects of pre-deformation and pre-aging on the mechanical properties of Al-Cu-Mg alloy with Sc and Zr addition were investigated. It is revealed that the introduction of pre-deformation can enhance the peak-aging strength, as well as tensile and yield strength, effectively due to the formation of finer and more dispersive precipitation. Pre-aging process before pre-deformation can increase the elongation while maintaining higher strength with a discontinuous distribution of precipitates at grain boundary. The precipitates of bean-like Al₃(Sc, Zr) particles further strengthen the alloy via pinning the dislocations which are formed during pre-deformation process and hindering the dislocation motion. Furthermore, pre-deformation and pre-aging accelerate the kinetics of precipitation due to preferential sites provided by the dislocation and the increase of GPB zones’ size and distribution. The synergism of pre-deformation and pre-aging achieves a combination of better mechanical properties and shorter peak-aging time.

The interaction between stress and galvanic during the corrosion process of 5050 aluminum alloys was studied and the evolution of mechanics properties was indicated. Electrochemical impedance technique and scanning electron microscopy were used to analyze the surface electrochemical states and the corrosion morphology. At the same time, corrosion kinetics and thermodynamic theory were used to analyze the influencing mechanism of the stress factor and the galvanic factor. The results show that both of galvanic factor and tensile stress factor can increase the corrosion potential of aluminum alloys and result in the corrosion resistance decrease. With decreasing corrosion resistance, the mechanical properties of aluminum alloys decrease. These phenomena are attributed to two reasons: One is that aluminum alloys may under the condition of anodic polarization after coupled with 40CrNiMoA steel, so the corrosion can be promoted; The other is that with increasing stress, the electrochemical potential of 5050 aluminum alloys decreases and the potential difference between two materials increases, so the corrosion becomes serious. Compared to the stress factor, the galvanic factor is significant.

The effects of hot-strip coiling temperature on Ti(C,N) precipitation, texture and hydrogen permeation behavior in DC06EK enamel steel were investigated by TEM, EBSD test and electrochemical hydrogen permeation experiment. It was found that the Ti(C,N) particles in hot-strip coarsened with increasing coiling temperature, whereas after cold-rolling and annealing, the size difference of Ti(C,N) particles was lessened. The hot-strip coiling temperature has a significant impact on the recrystallized texture in the subsequent cold-rolled and annealed sheet. Hot-strip using high temperature (700 °C) coiling leads to strong {111} recrystallized texture in annealed sheet, with peak intensity 9.2. On the contrary, in annealed sheets using hot-strip coiling at 650 °C, their {111} recrystallized textures were weaker, which was also reflected in their r _m values. Even though the hydrogen diffusion coefficient is slightly lower (7.76×10^-5 mm²/s) in annealed sheet using low temperature coiling (600 °C), appropriately higher coiling temperature is more suitable for DC06EK enamel steel combining both good drawability and fish-scale resistance.

Plasma electrolytic oxidation (PEO) coatings were prepared on AZ31 magnesium alloy using alkaline phosphate as base electrolyte system, and with the addition of sodium silicate (Na₂SiO₃), sodium aluminate (NaAlO₂) and potassium fluorozirconate (K₂ZrF₆) as additives. The microstructure, phase composition and element composition as well as surface profile of the PEO coatings were analyzed by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and threedimensional (3D) optical profilometry. The corrosion and wear properties were evaluated by electrochemical potentiodynamic polarization in 3.5 wt% NaCl solution and ball-on-disc wear tests, respectively. The results showed that the anions of the additives effectively participated in the coating formation influencing its microstructural features, chemical composition, corrosion resistance and tribological behaviour. It was observed that the sample treated by PEO in the electrolyte solution containing K₂ZrF₆ as an additive showed better corrosion and abrasive resistance.

In order to examine the effect of extrusion ratio on the microstructure and mechanical behavior in Al-Cu-Mg-Ag alloy, the Al-6.3Cu-0.48Mg-0.4Ag alloy was subjected to extruding with different extrusion ratios of 17, 30 and 67. The results indicate that the grains are refined and the strength is improved effectively with increasing extrusion ratio. However, further investigation shows that the extrusion ratio of 30 is more effective than the lower extrusion ratio (17) and the higher extrusion ratio (67) to refine the grains in the T6-temper alloy. Moreover, the sample with an extrusion ratio of 30 obtains more precipitates and superior mechanical properties after T6 treatment. This study supports the idea that there exists a critical extrusion ratio for grain refinement and improvement of mechanical properties for the T6-temper alloy. Recrystallization and precipitation during T6 treatment were introduced to explain the effects of extrusion ratio on the microstructure and mechanical properties of the Al-Cu-Mg-Ag alloys.

A novel semisolid continuous Micro Fused-Casting additive manufacturing technology for producing a ZL101 alloy strip was developed, Micro Fused-Casting means that the semisolid metal slurry was pressed out from the outlet of bottom of crucible to the movable plate. The degree of sub-cooling was easily provided by movement of substrate in the micro fused-casting area. Under the aid of 3D manufacturing software, the ZL101 alloy strip was solidified and formed layer by layer. The microstructure and properties of ZL101 semisolid slurry were improved by the cooling conditions. The results showed that the ZL101 alloy strip samples fabricated by Micro Fused-Casting had uniform structures and good performances with the substrate movement speed at 20 mm/s and the temperature at 590 °C, the ultimate tensile strength and elongation of the ZL101 alloy strip reached 242.59 MPa and 7.71%, while the average Vickers hardness was 82.55 HV.

In order to investigate the draping behavior of non-crimp fabrics (NCFs), two types of carbon NCFs with tricot-chain stitches or chain stitches were formed on a hemispherical mould via a stretch forming process. The shear angle and forming defects of the fabrics were measured on the hemisphere, under different blank holder forces (BHFs). The results showed that increasing BHF could enhance the shear angle slightly, reduce the asymmetry for the deformation of the fabrics, and change the main type of the process-induced defects. Besides, compression tests were performed on the corresponding composite components. By analyzing the change of fiber volume fraction and structural parameters of the textile reinforcements, the effects of draping behavior of NCFs on the mechanical performance of the composites were studied. The results reveal that draping process has distinguishable impacts on the mechanical properties of the final components, which is closely related to the stitching pattern of the NCFs.

As efficient water treatment agents, a novel series of rectorite-based ZnO and TiO₂ hybrid composites (REC/ZnO/TiO₂) were synthesized and characterized in this study. Effects of experimental parameters including TiO₂ mass ratio, solution pH and catalyst dosage on the removal of methyl blue (MB) were also conducted. The presence of a little mass ratio (2%-6%) of TiO₂ highly promoted the photoactivity of REC/ZnO/TiO₂ in removal of MB dye from aqueous solution, in which ZnO and REC played a role of photocatalyst and adsorbent. The promotion effects of TiO₂ may result from the accelerated separation of electron-hole on ZnO. The observed kinetic constant for the degradation of MB over REC/ZnO and REC/ZnO/TiO₂ were 0.015 and 0.038 min^-1, respectively. The degradation kinetics of MB dye, which followed the Langmuir–Hinshelwood model, had a reaction constant of 0.17 mg/(L·min). The decrease of removal ratio of MB after five repetitive experiments was small, indicating REC/ZnO/TiO₂ has great potential as an effective and stable catalyst.

A novel quaternary ammonium chitosan hydrogel modified by poly(amidoamine) (PAMAM) dendrimer was prepared by using glutaraldehyde as a cross-linker. The hydrogel was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results confirmed its highly porous three-dimensional network structure. The swelling test of hydrogel proved that it had excellent swelling and pH-sensitive properties. The increasing PAMAM content or quaternization degree led to the increase in swelling properties. And the hydrogel with lower cross-linking agent concentration or quaternary ammonium chitosan concentration exhibited better swelling properties. The antibacterial results indicated that with the increase in the PAMAM content, quaternary ammonium chitosan concentration or cross-linking agent concentration, the hydrogels showed better antibacterial activities against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Thus, the hydrogel could serve as a promising antibacterial material in the future.

A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-(4-hydroxyphenyl) terahydrophthalic anhydrideimide (HTAM) was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4’-diaminodiphneylmethane (DDM) was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses (DMA) and thermogravimetric analysis (TGA). The results showed that the cured resin exhibited a high glass transition temperature (T _g) of 186 °C when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 °C raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.

Polypropylene (PP) composites that contain silver micro-particles (MILLION KILLER, denoted as Ag-Ms) and conductive carbon black (CB) have both antibacterial and antistatic properties. In the present study, the antibacterial and antistatic PP/Ag-Ms/CB composites were prepared by melt blending. The results showed that when the content was 0.8 wt%, Ag-Ms could be uniformly dispersed in the PP matrix and the mechanical properties of the composites remained stable. And the reduction percentages of Staphylococcus aureus and Escherichia coli were more than 80% which showed the good antibacterial behavior. In addition, conductive carbon black had reinforcing and toughening effects on the mechanical properties of PP/Ag-Ms/CB composites. When the content of CB was beyond 30 wt%, the surface resistance of the composite was reduced to less than 108 Ω which showed a remarkable antistatic property. According to the different filling content of conductive carbon black, it can flexibly regulate the resistivity of PP, and the conductive effect is durable and stable. We thus can produce permanent antistatic materials.

An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.