A series of spinel-type Mg_0.25−xAl_2.57O_3.79N_0.21:xMn²⁺ (MgAlON:xMn²⁺) phosphors were synthesized by the solid-state reaction route. The transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing (HIP). The crystal structure, luminescence and mechanical properties of the samples were systematically investigated. The transparent ceramic phosphors with tetrahedrally coordinated Mn²⁺ show strong green emission centered around 515 nm under blue light excitation. As the Mn²⁺ concentration increases, the crystal lattice expands slightly, resulting in a variation of crystal field and a slight red-shift of green emission peak. Six weak absorption peaks in the transmittance spectra originate from the spin-forbidden ⁴T₁(⁴G)→⁶A₁ transition of Mn²⁺. The decay time was found to decrease from 5.66 to 5.16 ms with the Mn²⁺ concentration. The present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn²⁺ green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes.

The glass-ceramics were prepared with the spodumene mineral as the main raw material, and the effects of ZrO₂ replacing TiO₂ on the samples were systematically investigated. The results show that the substitution of ZrO₂ for TiO₂ is not conductive to precipitate β-quartz solid solution phase, but can improve the transparency and flexural strength of glass-ceramics. And the glass-ceramic with the highest visible light transmittance (87%) and flexural strength (231.80 MPa) exhibits an ultra-low thermal expansion of −0.028×10⁻⁷ K⁻¹ in the region of 30–700 °C.

The presence of Li₂Si₂O₅ and LiAlSi₄O₁₀ could effectively improve the elastic modulus and transmittance of lithium disilicate(LD) glass-ceramics. Through synergistically modulation of the crystal content and grain size, we obtained high strength and high transmittance of LD glass-ceramics. The optimal sample had a high transmittance of 90.3%, the hardness was 7.72 GPa, the fracture toughness was 1.07 MPa·m^1/2, and the elastic modulus was 103.1 GPa.

A machine learning (ML)-based random forest (RF) classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO₃-based ceramics and their interpretability was analyzed by using Shapley additive explanations (SHAP). An F1-score changed from 0.879 5 to 0.931 0, accuracy from 0.845 0 to 0.907 0, precision from 0.871 4 to 0.900 0, recall from 0.892 9 to 0.964 3, and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features, demonstrating the high accuracy of our model and its high robustness. During the interpretability analysis of the model, it was found that the electronegativity, melting point, and sintering temperature of the dopant contribute highly to the formation of the core-shell structure, and based on these characteristics, specific ranges were delineated and twelve elements were finally obtained that metall the requirements, namely Si, Sc, Mn, Fe, Co, Ni, Pd, Er, Tm, Lu, Pa, and Cm. In the process of exploring the structure of the core-shell, the doping elements can be effectively localized to be selected by choosing the range of features.

To study the damage and failure of shale with different fracture inclination angles under uniaxial compression loading, in this work, RFPA2D-Thermal, a two-dimensional real failure process analysis software, was used for numerical simulation. Numerical simulation results show that quartz in shale mainly affects the tensile and compressive strength of shale by increasing rock brittleness. The coupling of temperature and pressure will cause lateral and volume destruction of shale, which enables the shale body to be more easily broken. Fracture inclination is the key factor affecting shale damage patterns. The failure mode of shale with low- and high-angle fractures is mainly shear failure, and the compressive strength does not vary with crack inclination. The damage mode of obliquely intersecting fractured shale is slip damage along the fracture face, the compressive strength decreases and then increases with the fracture inclination, and a minimum value exists. The acoustic emission simulation results of the damage process effectively reflect the accumulated internal damage and macroscopic crack appearance until fracture instability when the prefabricated fractured shale is subjected to uniaxial compressive loading. The crack inclinations of 0° and 120 °C corresponds to the most complex “N” shape damage mode. The crack inclinations of 30° and 60°, and the damage mode is an inverted “λ” shape.

In this study, transparent K₂O-Al₂O₃-SiO₂ (KAS) glass-ceramics with leucite as the main crystalline phase were prepared by melting-quench method and two-step heat treatment. The effects of SiO₂/Al₂O₃ ratio and heat treatment on crystallization and mechanical properties were studied. The crystallization kinetics and X-Ray Diffraction (XRD) results showed that SiO₂/Al₂O₃ ratio and heat treatment system had a direct impact on the crystallization behavior of potassium aluminosilicate glass-ceramics. When heat-treated at 680 °C/2 h and 780 °C/1 h, cracks generated on the surface of the sample with the addition of SiO₂/Al₂O₃ = 4.8 (in mol) due to the huge difference in the coefficient of thermal expansion between glass matrix and surface. When the addition of SiO₂/Al₂O₃ (in mol) was 4, the sample with leucite as the main crystalline phase showed an excellent fracture toughness (1.46 MPa·m⁰⁵) after the heat treatment of 680 °C/2 h and 780 °C/5 h. And there was a phase transformation from kaliophilite to leucite. The crystalline phases of the sample heat-treated at 680 °C/8 h and 780 °C/1 h were leucite and kaliophilite, which resulted in the visible light transmittance of 63% and the fracture toughness of 0.91 MPa·m^0.5. Furthermore, after the heat treatment of 680 °C/2 h and 780 °C/5 h, the main crystalline phase of the sample with SiO₂/Al₂O₃ = 3.2 (in mol) was still kaliophilite. Because leucite only grows on the surface of the sample and is hard to grow inward, it is hard to achieve the bulk crystallization of leucite in the sample with SiO₂/Al₂O₃ = 3.2 (in mol).

Bacterial cellulose (BC) was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester [P(AM-co-SBMA)] to build a dual-network porous structure gel polymer electrolytes (GPEs) with high ionic conductivity. The dual network structure BC/P(AM-co-SBMA) gels were formed by a simple one-step polymerization method. The results show that ionic conductivity of BC/P(AM-co-SBMA) GPEs at the room temperature are 3.2×10⁻² S/cm @1 M H₂SO₄, 4.5×10⁻² S/cm @4 M KOH, and 3.6×10⁻² S/cm @1 M NaCl, respectively. Using active carbon (AC) as the electrodes, BC/P (AM-co-SBMA) GPEs as both separator and electrolyte matrix, and 4 M KOH as the electrolyte, a symmetric solid supercapacitors (SSC) (AC-GPE-KOH) was assembled and testified. The specific capacitance of AC electrode is 173 F/g and remains 95.0% of the initial value after 5 000 cycles and 86.2% after 10,000 cycles.

In this work, the structure, viscosity and ion-exchange process of Na₂O-MgO-Al₂O₃-SiO₂ glasses with different Al₂O₃/SiO₂ molar ratios were investigated. The results showed that, with increasing Al₂O₃/SiO₂ ratio, the simple structural units Q₁ and Q₂ transformed into highly aggregated structural units Q₃ and Q₄, indicating the increase of polymerization degree of glass network. Meanwhile, the coefficient of thermal expansion decreased from 9.23×10⁻⁶ °C⁻¹ to 8.88×10⁻⁶ °C⁻¹. The characteristic temperatures such as melting, forming, softening and glass transition temperatures increased with the increase of Al₂O₃/SiO₂ ratio, while the glasses working temperature range became narrow. The increasing Al₂O₃/SiO₂ ratio and prolonging ion-exchange time enhanced the surface compressive stress (CS) and depth of stress layer (DOL). However, the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation. There was a good linear relationship between stress relaxation and surface compressive stress. Chemical strengthening significantly improved the hardness of glasses, which reached the maximum value of (622.1 ° 10) MPa for sample with Al₂O₃/SiO₂ ratio of 0.27 after heat treated at 410 °C for 2 h.

The natural Melanin/TiO₂ was synthesized by the use of ultrasonication under UV radiation. The influence of natural melanin on the structural, optical and thermal properties of TiO₂ nanoparticles was investigated by using Fourier transform infrared spectroscopy, thermogravimetric analysis and UV-Vis spectroscopy. It was observed that incorporating natural melanin on TiO₂ nanoparticles (TiO₂-Mel) occurred at 2.01 eV with a low value of Urbach energy around 100 meV indicating improvement in the crystalline structure. Magnetic measurement at room temperature showed diamagnetic behavior. Furthermore, thermal results showed that TiO₂-Mel is stable even at temperatures up to 400 °C. According to the results obtained by the thermal stability of melanin with titanium dioxide, it can be a good candidate in many applications such as solar cells and optoelectronics.

α-Fe₂O₃/epoxy resin composite superhydrophobic coating was prepared with α-Fe₂O₃ nanoparticles and epoxy resin by spin coating method. The coating without epoxy resin has higher contact angle (CA) and lower ice adhesion strength (IAS), but the mechanical properties are poor. The α-Fe₂O₃/epoxy resin composite superhydrophobic coating exhibits good mechanical durability. In addition, compared with the bare aluminum substrate, the E _corr of the composite coating is positive and the J _corr is lower. The inhibition efficiency of the composite coating is as high as 99.98% in 3.5 wt% NaCl solution. The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.

In order to explore the effect of vacancy defects on the structural, electronic, magnetic and optical properties of CoS₂ and FeS₂, first-principles calculation method was used to investigate the alloys. The calculated results of materials without vacancy are consistent with those reported in the literatures, while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration. The Co vacancy defect hardly changes the half-metallic characteristic of CoS₂. The Fe vacancy defect changes FeS₂ from semiconductor to half-metal, and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_2g) orbital state of Fe, while the top of the valence band remains the d orbital d(e_g) state of Fe. The half-metallic Co vacancy defects of CoS₂ and Fe vacancy defects of FeS₂ are expected to be used in spintronic devices. S vacancy defects make both CoS₂ and FeS₂ metallic. Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS₂, while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS₂. Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously, and produce obvious red shift phenomenon, which is expected to be used in photoelectric devices.

The structures, mechanical properties and electronic structures of M metals (M=Ti, V, Cr, Mn and Fe) doped β-Si₃N₄ were investigated by First-principles calculations within CASTEP. The calculated lattice parameters of β-Si₃N₄ were consistent with previous date. The cohesive energy and formation enthalpy show that initial β-Si₃N₄ has the highest structural stability. The calculated elastic constant and the Voigt-Reuss-Hill approximation indicate that elastic moduli of β-Si₃N₄ are slightly reduced by M doping. Based on Poisson’s and Pugh’s ratio, β-Si₃N₄ is a ductile material and the toughness of β-Si₃N₄ increases with M doping, and Fe doping exhibited the best toughness. The results of density of states, charge distributions and overlapping populations indicate that β-Si₃N₄ has the strong covalent and ionic bond strength between N and Si.

Boron carbide has unique properties for wide application possibilities; however, poor sinterability limits its applications. One approach to overcome this limitation is the addition of secondary phases into boron carbide. Boron carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering additive. The present study investigated the effect of Ti₃SiC₂ addition to boron carbide by reactive spark plasma sintering in the range of 1 700–1 900 °C. Ti₃SiC₂ phase decomposed at high temperatures and reacted with B₄C to form secondary phases of TiB₂ and SiC. The results demonstrated that the increase of Ti₃SiC₂ addition (up to 15 vol%) effectively promoted the densification of B₄C and yielded higher hardness. However, as the amount of Ti₃SiC₂ increased further, the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.

We used the surface-pretreated graphite paper (Gp) as a carrier and loaded BiOCl with high selectivity to Cl⁻ on its surface by solvothermal method to form BiOCl@Gp electrode. The morphology, structure, and composition of the materials were characterized by scanning electron microscopy and nitrogen adsorption/desorption, and the results showed that the spherical BiOCl particles were uniformly dispersed on the surface of the Gp, forming a mesoporous BiOCl@Gp composite with a specific surface area of 22.82 m²/g and a pore volume of 0.043 cm³/g. Furthermore, cyclic voltammetry and electrochemical impedance spectroscopy were used to test the electrochemical properties of the composites, and the stability of BiOCl and the high conductivity of Gp were synergistic, the BiOCl@Gp exhibited a specific capacitance of 30.2 F·g⁻¹ at a current density of 0.5 A·g⁻¹, and the selectivity of the BiOCl@Gp materials for Cl− was significantly higher than that of SO₄ ²⁻, NO₂ ⁻, and HCO₃ ⁻. Therefore, BiOCl@Gp composite electrode materials can be used for the selective adsorption of Cl⁻ in wastewater, in order to achieve efficient wastewater recycling.

In this work, flexible photothermal PVA/Ti₂O₃ composite films with different amount (0 wt%, 5 wt%, 10 wt%, 15 wt%) of Ti₂O₃ particles modified by steric acid were prepared by a simple solution casting method. The microstructures, XRD patterns, FTIR spectra, UV-Vis-NIR spectra thermo-conductivity, thermostability and photothermal effects of these composite films were all characterized. These results indicated that Ti₂O₃ particles were well dispersed throughout the polyvinyl alcohol (PVA) matrix in the PVA/Ti₂O₃ composite films. And Ti₂O₃ particles could also effectively improve the photothermal properties of the composite films which exhibited high light absorption and generated a high temperature (about 57.4 °C for film with 15 wt% Ti₂O₃ amount) on the surface when it was irradiated by a simulated sunlight source (1 kW/m²).

WC-Co nanocrystalline nitrogen-containing cemented carbides were prepared by vacuum sintering and low pressure sintering. The sintering processes of Cr₂(C,N) doped nano WC-Co powders were studied by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of sintering temperature on the microstructure and mechanical properties of nanocrystalline cemented carbide was studied by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM) and mechanical property test. The results showed that the nano WC grains began to grow in the solid phase sintering stage. A high-performance nano-nitrogen-containing cemented carbide with uniform microstructure and good interfacial bonding can be obtained by increasing the sintering temperature to 1 380 °C. It has a transverse rupture strength (TRS) of 5 057 MPa and a hardness of 1 956 HV30.

We developed ultra-high performance concrete (UHPC) incorporating mullite sand and brown corundum sand (BCS), and the quartz sand UHPC was utilized to prepare for comparison. The properties of compressive strength, elastic modulus, ultrasonic pulse velocity, flexural strength, and toughness were investigated. Scanning electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic performance. Due to the superior interface bonding properties between mullite sand and matrix, the compressive strength and flexural toughness of UHPC have been significantly improved. Mullite sand and BCS aggregates have higher stiffness than quartz sand, contributing to the excellent elastic modulus exhibited by UHPC. The stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance, and the latter contributes more to the strength of UHPC. This study will provide a reference for developing UHPC with superior elastic modulus for structural engineering.

A composite bone cement based on α-TCP with self-reinforcing characteristics is prepared by compounding cellulose whiskers and polyvinyl alcohol in different proportions. In this system, we are inspired by the sea cucumber, which can alter the stiffness of their inner dermis reversibly. Through the formation of hydrogen bonds between the hydroxyl groups on the cellulose whiskers and PVA, the bone cement matrix can be strengthened during the curing process of cement. In the process of bone cement blending, there is more water, the hydrogen bond connection is destroyed, so the slurry has better fluidity at this time. As the hydration of the bone cement progresses, the reduction of the water phase leads to the formation of a permeable network structure of hydrogen bond connections between the whiskers. The dual-phase action of PVA and whiskers greatly increases the mechanical strength of the bone cement system (5.5 to 23.8 MPa), while the presence of polyvinyl alcohol improves the toughness of the bone cement system. This work was supposed to explore whether the chemoresponsive materials can be adapted to biomedical materials, for example, bone repair.

Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete. In this paper, microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM, the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM, and the strengthening mechanism was analyzed. The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate. It is suggested that the replacement rate of recycled powder should not exceed 20%. The strength index and activity index of carbonated recycled powder mortar were improved, in which the flexural strength was increased by 27.85% and compressive strength was increased by 20% at the maximum. Recycled powder can be quickly and completely carbonated, and the improvement effect of CH pre-soaking carbonation was the best. The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder. Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect, alkaline polycondensation effect and carbonation enhancement effect.

This study aims to investigate the feasibility of using decoration waste powder (DWP) as a partial replacement for fly ash (FA) in the preparation of geopolymer masonry mortar, and to examine the effect of different DWP replacement rates (0%–40%) on the fresh and mechanical properties of the mortar. The results showed that each group of geopolymer masonry mortar exhibited excellent water retention performance, with a water retention rate of 100%, which was due to the unique geopolymer mortar system and high viscosity of the alkaline activator solution. Compared to the control group, the flowability of the mortar containing lower contents of DWP (10% and 20%) was higher. However, as the DWP replacement rate further increased, the flowability gradually decreased. The DWP could absorb the free water in the reaction system of geopolymer mortar, thereby limiting the occurrence of geopolymerization reaction. The incorporation of DWP in the mortar resulted in a decrease in compressive strength compared to the mortar without DWP. However, even at a replacement rate of 40%, the compressive strength of the mortar still exceeded 15 MPa, which met the requirements of the masonry mortar. It was feasible to use DWP in the geopolymer masonry mortar. Although the addition of DWP caused some performance loss, it did not affect its usability.

The objective of this paper was to study low temperature crack resistance mechanism of steel slag asphalt mixture(SAM). Thermal stress restrained specimen test (TSRST) and three-point bending test were carried out to evaluate the low-temperature crack resistance of SAM and basalt asphalt mixture (BAM). Based on the digital image correlation technique (DIC), the strain field distribution and crack propagation of SAM were analyzed from the microscopic point of view, and a new index, crack length factor (C), was proposed to evaluate the crack resistance of the asphalt mixture. The crystal phase composition and microstructure of steel slag aggregate (SA) and basalt aggregate (BA) were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to explore the low-temperature crack resistance mechanism of SAM. Results show that the low-temperature crack resistance of SAM is better than that of BAM; SAM has good integrity and persistent elastic deformation, and its bending failure mode is a hysteretic quasi-brittle failure; The SA surface is evenly distributed with pores and has surface roughness. SA has the composition phase of alkaline aggregate-calcite (CaCO₃), so it has good adhesion to asphalt, which reveals the mechanism of excellent low-temperature crack resistance of SAM.

This study explored the synergistic interaction of sewage sludge (SS) and automotive paint sludge (PS) during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems, utilizing thermogravimetric analysis (TGA) and thermogravimetric-mass spectrometry (TGA-MS). The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS. The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS, while the main source of the antagonistic effect is that, during the mechanical mixing process, the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect, hindering the volatilization of volatile components. SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas. This study will provide some in-depth insights into the co-pyrolysis of SS/PS, and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.

The modification methods of pozzolan slurry combined with sodium silicate and silicon-based additive were respectively adopted to treat recycled coarse brick-mixed aggregate (RCBA) in this study. The compressive strength and chloride permeability resistance of recycled aggregate concrete (RAC) before and after modification treatment were tested, and the microstructure of RAC was analyzed by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results show that the physical properties of RCBA strengthened by modification treatment are improved, and the compressive strength and chloride permeability resistance of treated RAC are also significantly improved. The modification treatment optimizes the pore size distribution of RAC, which increases the number of gel pores and transition pores, and decreases the number of capillary pores and macro pores. The surface fractal dimension shows a significant correlation with chloride diffusion coefficient, indicating that the variation of chloride permeability of treated RAC is consistent with the microstructure evolution.

The improved microstructure and enhanced elevated temperature mechanical properties of Ti-44Al-5Nb-(Mo, V, B) alloys were obtained by vacuum arc re-melting (VAR) and primary annealing heat treatment (HT) of 1 260 °C/6 h/Furnace cooling (FC). The phase transformation, microstructure evolution and tensile properties for as-cast and HTed alloys were investigated. Results indicate that three main phase transformation points are determined, T _eut=1 164.3 °C, T _{γ solv} = 1 268.3 °C and T _{β trans} = 1 382.8 °C. There are coarse lamellar colonies (300 µm in length) and neighbor reticular B2 and γ grain (3–5 µm) in as-cast alloy, while lamellar colonies are markedly refined and multi-oriented (20–50 µm) as well as the volume fraction and grain sizes of equiaxed γ and B2 phases (about 15 µm) significantly increase in as-HTed alloy. Phase transformations involving α+γ→α+γ+β/B2 and discontinuous γ coarsening contribute to the above characteristics. Borides (1–3 µm) act as nucleation sites for β _eutectic and produce massive β grains with different orientations, thus effectively refining the lamellar colonies and forming homogeneous multi-phase microstructure. Tensile curves show both the alloys exhibit suitable performance at 800 °C. As-cast alloy shows a higher ultimate tensile stress of 647 MPa, while a better total elongation of more than 41% is obtained for as-HTed alloy. The mechanical properties improvement is mainly attributed to fine, multi-oriented lamellar colonies, coordinated deformation of homogeneous multi-phase microstructure and borides within lamellar interface preventing crack propagation.

In the present study, the Cu-(1 wt%–6 wt%) Ag alloys were prepared by melting, forging and wire drawing. The effects of plastic deformation on microstructure evolution and properties of the alloys were investigated. The results show that non-equilibrium eutectic colonies exist in the Cu- (3 wt%–6 wt%) Ag alloy and no eutectic colonies in the 1 wt%–2 wt% Ag containing alloys. These eutectic colonies are aligned along the drawing direction and refined with the increase of draw ratio. Attributed to the refinement of eutectic colonies, the Cu-Ag alloy exhibits higher strength with the increase of draw ratio. The Cu-6Ag alloy exhibits excellent comprehensive properties with a strength of 930 MPa and a conductivity of 82 %IACS when the draw ratio reaches 5.7.

To understand the hot compression deformation characteristics of the self-developed Al-9.3Zn-2.4Mg-1.1Cu alloy, the hot compression tests of Al-9.3Zn-2.4Mg-1.1Cu alloy were investigated by Gleeble 1500 thermo-mechanical simulator to determine the best hot processing conditions. The hot deformation temperatures were 300, 350, 400, and 450 °C, and the strain rates were 1, 0.1, 0.01, and 0.003 s⁻¹, respectively. Based on the experimental results, the constitutive equation and hot processing maps are established, and the corresponding strain rate and temperature-sensitive index are analyzed. The results show that Al-9.3Zn-2.4Mg-1.1Cu alloy has a dynamic softening trend and high strain rate sensitivity during the isothermal compression process. The hot deformation behavior can be described by an Arrhenius-type equation after strain compensation. The temperature has a negligible effect on the hot processing properties, while a low strain rate is favorable for the hot working of alloy. The processing maps and microstructure show that the optimal processing conditions were in the temperature range of 400–450 °C and strain rate range of 0.003–0.005 s⁻¹.

The as-cast Mg-2.0Zn-1.5Sn-xZr(x= 0,0.4, 0.6, 0.8, 1.0 wt%) alloy was rolled with the pressure less than 5% each time. The microstructure, mechanical properties, corrosion properties and biocompatibility of the alloy were investigated. The microstructure of the alloy was observed and analyzed by scanning electron microscope, and the tensile test was carried out by universal tensile machine. The corrosion resistance of the alloy in Hank’s solution was studied by hydrogen evolution experiment and electrochemical test, and the biocompatibility of the alloy was tested by L929 cells. The results show that Mg-2Zn-1.5Sn-xZr alloy has excellent mechanical properties. The elongation of Mg-2Zn-1.5Sn-xZr alloy decreases with the increase of Zr content, but the tensile strength first increases and then decreases with the increase of Zr concentration. When the Zr content is 0.8 wt%, the maximum tensile strength of the alloy is 235 MPa. The results of hydrogen evolution experiment and electrochemical analysis show that the corrosion resistance of the alloy is the best when the Zr content is 0.8 wt%, and all the five alloys have high biocompatibility. In conclusion, the rolled alloy has good properties and has broad application prospects in the field of biomaterials.

In this study, pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy (HSLA) specimens with four kinds of grain size. Effect of pre-strain and grain size on mechanical property was investigated through tensile tests. Microstructures of the pre-strained and tensile tested samples were analyzed, respectively. The 30.8° v-bending and following flattening, as well as Erichson cupping tests, were performed on the pre-strained samples. Results show the elongation ratio of grain and dislocation density increases with pre-strain. Yielding platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning effect. The 30.8° v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain size. Decrease in grain size, along with increase in pre-strain, causes increase in strength and decrease in elongation rate as well as cupping value. Pre-strain causes very slight effect on bending ability, much less than that on mechanical property and cupping test value. Reciprocal impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.

By using 6,6-((sulfonylbis (4,1-phenylene)) bis (azanediyl)) bis (thiophen-2-ylm- ethylene)) bis (6H-di-benzo[c,e][1,2]oxaphosphinine 6-oxide (DOPO-N) as phosphorus-nitrogen flame retardant, the polyurea (PUA) with flame retardant properties (PUA/DOPO-N) was prepared. In addition, organically modified montmorillonite (OMMT) and magnesium hydroxide (MH) were used as co-effectors respectively, and the flame retardant PUA (PUA/DOPO-N/OMMT and PUA/DOPO-N/MH) were also prepared. Thermal properties, flame retardant properties, flame retardant mechanism and mechanical properties of PUA/DOPO-N, PUA/DOPO-N/OMMT and PUA/DOPO-N/MH were investigated by thermogravimetric (TG) analysis, limiting oxygen index (LOI), UL 94, cone calorimeter test, scanning electron microscopy (SEM), and tensile test. The results show that the LOI value of PUA/20%DOPO-N, PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are 27.1%, 27.7%, and 28.3%, respectively, and UL 94 V-0 rating is attained. Compared with PUA, the peak heat release rate (pk-HRR), total heat release (THR) and average effective heat combustion (av-EHC) of PUA/20%DOPO-N, PUA/18% DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH decrease significantly. SEM results indicate that the residual chars of PUA/20%DOPO-N, PUA/18%DOPO-N/2%OMMT and PUA/15% DOPO-N/5%MH are completer and more compact. The complex of DOPO-N/OMMT and DOPO-N/MH have synergistic flame retardancy. The mechanical properties of PUA can be improved by the addition of DOPO-N, DOPO-N/OMMT and DOPO-N/MH, respectively. The insulation performance test shows that the volume resistivity of PUA/20%DOPO-N is 6.25×10¹⁶ Ω.cm. Furthermore, by using modified boron nitride (MBN) as heat dissipating material, the complex of PUA/MBN was prepared, and the thermal conductivity of PUA/MBN was investigated. The thermal conductivity of PUA/8%MBN complex coating at room temperature is 0.166 W/(M·K), which is a 163% improvement over pure PUA.

Super absorbent resin (SAR) is prepared by aqueous high temperature polymerization using hydroxypropyl methylcellulose (HPMC) as monomer backbone material, acrylic acid (AA) and acrylamide (AM) as the graft copolymer monomer, potassium persulfate (KPS) as the initiator to generate free radicals, and N, N′-methylenebisacrylamide (MBA) as cross-linking agent for cross-linking reaction. Simutaneously, the influence of individual factors on the water absorption is investigated, and these factors are mainly AA, AM, KPS, MBA, HPMC, and reaction temperature. The optimized conditions are obtained by the experiment repeating for several times. The water absorption multiplicity and salt absorption multiplicity under the conditions are 782.4 and 132.5 g/g, respectivity. Furthermore, the effects of different temperatures and salt concentrations on its water absorption, as well as the swelling kinetics of SAR are studied. It is indicated the water-absorbing swelling process is mainly caused by the difference in water osmotic pressure and Na⁺ concentration inside and outside the cross-linked molecular structure of the resin, which is not only consistent with the quasi-secondary kinetic model, but also with the Fick diffusion model.

The objective of this research was to determine the mechanical parameter from EVA foam and also investigate its behavior by using Blatz-Ko, Neo-Hookean, Mooney model and experimental test. The physical characteristic of EVA foam was also evaluated by scanning electron microscopy (SEM). The results show that Blatz-Ko and Neo-Hookean model can fit the curve at 5% and 8% strain, respectively. The Mooney model can fit the curve at 50% strain. The modulus of rigidity evaluated from Mooney model is 0.081 4 ± 0.002 7 MPa. The structure of EVA foam from SEM image shows that EVA structure is a closed cell with homogeneous porous structure. From the result, it is found that Mooney model can adjust the data better than other models. This model can be applied for mechanical response prediction of EVA foam and also for reference value in engineering application.