As a burnable poison element, boron (B) has been successfully added into the AlNbMoZr based refractory high-entropy alloy (RHEA) via arc melting method, thus a novel high strength nuclear RHEA material with neutron toxic properties was developed. Hence, the alloy was subjected to irradiation of Kr ions of 4 MeV intensity to assess its irradiation damage behavior in terms of its microstructure and mechanical property evolution. The results of room temperature compression testing show that AlNbMoZrB alloy has excellent mechanical property with compression yield strength ~1180 MPa, fracture strength ~1274 MPa, and plasticity ~4.8%. By comparatively examining the phase structure and microstructure evolution of AlNbMoZrB alloy before and after irradiation, it is found that AlNbMoZrB alloy has a typical dendrite structure, in which the dendrite region is a matrix phase with disordered BCC structure, and the interdendrite region is composed of FCC structure Al-Zr phase and α-Zr phase. After irradiation with Kr ions, the α-Zr phase underwent an amorphous transformation. At the same time, high density <100> and 1/2<111> dislocation loops are also generated. The volume density of the dislocation loop is ~4.11×10²² m^-3 and the size is between 12 nm and 16 nm after subjected Kr ions irradiation at room temperature. The volume density of the dislocation loop decreased to ~1.63×10²² m^-3 and the size increased to 23~27 nm after subjected the same Kr ions irradiation at 300℃.

The metal-organic skeleton compound MIL125 was prepared with terephthalic acid and isopropyl titanate as raw materials, afterwards by post impregnating in alkaline metal chloride solution, a series of alkali metal cation-doped M@MIL125-t (M: Li⁺, Na⁺, K⁺; t: 6 h, 9 h, 12 h) were obtained. They were characterized by X-ray diffractometer, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Their specific surface area and CO₂ adsorption capacity were assessed by nitrogen isothermal adsorption-desorption curve and CO₂ adsorption curve measurements. The results showed that being impregnated with alkali metal chloride solution, the structure and crystal form of MIL125 has not changed significantly. The surface and pores of MIL125 grain was corroded by the impregnation solution, and the specific surface area increased first and then decreased. The optimum impregnation time of MIL125 in the three alkali metal chloride solutions was 9 h. When doped with Na⁺ by impregnating for 9 h, the maximum specific surface area is up to 2497 m²/g, which is 81.5% higher than that of blank MIL125, and the CO₂ adsorption amount is 1.41 mmol/g, which is 72.0% higher than that of blank MIL125.

Hot deformation behavior and microstructure evolution of super austenitic stainless steel 24Cr-22Ni-7Mo-0.4N were studied by uniaxial compression tests at temperatures from 1123 K to 1473 K under strain rates of 0.001~10 s^-1 up to the true strain of 0.8. The deformation parameters were modeled by Arrhenius equation and Zener-Hollomon parameter (Z). The peak stress and critical stress for dynamic recrystallization was found to exhibit a linear relationship with ln(Z/A), the thermal deformation activation energy of the steel was 497.11 kJ/mol. Based on the dynamic material model, the processing maps under different plastic strains were established. Electron backscatter diffraction (EBSD) was used to characterize the microstructure of the steel under different deformation conditions. The softening mechanism of the steel under most deformation conditions is discontinuous dynamic recrystallization (DDRX). Based on the analysis of microstructure and processing map, the optimum processing domain for hot deformation is identified as the deformation temperature of 1150~1200℃ and strain rate of 0.1~1 s^-1.

The effect of plasma surface modification and plasma grafting modification on the inhomogeneity of interfacial properties of the modified carbon fiber/epoxy composites was comparatively studied by means of interlaminar shear strength (ILSS) test, metallography, SEM, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIS) in terms of the relevant affecting factors. Firstly, the interlaminar shear strength (ILSS) of the composites was measured and its variation was evaluated.Results showed that the enhancement rate of ILSS by plasma surface modification was only 8.6%, while that by plasma grafting was 37% by the same plasma treatment conditions. However, compared with the plasma surface modification, the plasma graft modification aggravated the dispersion of ILSS. Then the surface morphology and the adhesion situation to the resin matrix of the carbon fibers modified by the two methods were studied by scanning electron microscope and metallographic microscope, respectively. Fourier transform infrared spectroscopy was used to reveal the chemical reactions on the fiber surface. The results showed that compared with the plasma surface modification, the plasma grafting modification could graft more active groups onto carbon fibers through substitution reaction, which may result in the improvement of interfacial properties. However, due to the inhomogeneity of grafting layer, which may cause the increase of the fiber adhesion and aggregation, thereby the ILSS dispersion of composites after grafting modification was expanded. Therefore, the control of plasma grafting modification on the homogeneity of interfacial property for composites deserves more attention. This study can provide some theoretical guidance for composite interface modification and its homogeneitycontrol.

Hollow spherical AlOOH was successfully prepared by template-free hydrothermal method employing Al₂(SO₄)₃ and urea as raw materials. The appropriate preparation conditions were obtained after determining the influence of Al³⁺/urea molar ratio, hydrothermal temperature, time and Al³⁺ concentration on the structure and morphology of the prepared AlOOH. The hollow spherical structure consisted of a large number of nanoflakes possesses a high specific surface area and a total pore volume, whose formation is a process involving precipitation, dissolution and recrystallization. Hollow spherical AlOOH exhibits excellent adsorption capacity for Congo red with the adsorption equilibrium of 10 min and the maximal adsorption capacity of 253.81 mg·g^-1. The adsorption capacity still maintains a high level after 4 times of recycling. The pseudo-second-order model fits the adsorption process well. Both the Langmuir and Freundlich models fit the adsorption well.

VCoNi medium entropy alloy (MEA) with severe lattice distortion has good strength and toughness. In this work, the MEAs (VCoNi)_100-x C _x (x=0, 0.1, 0.4, 1 and 2.8) were repaired by the following processes: the mixture of alloy powders was melted per vacuum non-consumable arc melting furnace; Then the as-cast alloy was subjected to thermal compression deformation (45% deformation) after being heated at 1000℃ for 2 h; further rolling deformation at room temperature (70% deformation); which was finally heated at 1000℃ for 1 min followed by water quenching to acquire the recrystallized alloys. Then the effect of different C additions on the microstructure, mechanical and wear properties of the MEAs was systematically studied via SEM with EDS and EBSD, universal tensile testing machine and pin/disc wear tester. The results show that when the C content is between 0 and 1, with the increase of C content, the grain size of both the homogenized and recrystallized EMAs decrease, while the amount of second phase particles increases. For the homogenized EMAs, textures converge gradually toward the ɑ-orientation; while for recrystallized EMAs, textures converge on the-orientation, where is the strongest point of the textures also situated. When the C content is between 1 and 2.8, coarse cellular grains emerge in the homogenized EMAs, while the second phases precipitate as coexisting rods and particulates, however the annealing twinning is sharply reduced, and no typical texture type exists. The tensile test results show that (VCoNi)_99.9C_0.1 exhibits an optimal strength-ductility balance, which may be attributed to the appropriate size and distribution of the particles, resulting in fine grain strengthening, interstitial strengthening and particles strengthening. The friction and wear test results show that the wear property of the EMAs is improved due to the C addition, which is mainly attributed to the weakened abrasive wear mechanism and the enhanced adhesive and oxidative wear mechanisms. Therefore, the addition of appropriate amount of C is conducive to optimize the microstructure of (VCoNi)MEA and further improve the mechanical and wear properties.

Mg-alloys Mg97Y1.5Er0.5Ni1, Mg97Y1Er1Ni1 and Mg97Y0.5Er1.5Ni1 were fabricated by gravity casting method. Then the microstructure and tensile properties of the as-cast and solution-treated (520℃, 12 h) alloys were investigated by means of SEM with EDS, TEM and electronic universal testing machine. The results show that the as-cast alloys Mg97Y1.5Er0.5Ni1, Mg97Y1Er1Ni1 and Mg97-Y0.5Er1.5Ni1 are mainly composed of α-Mg matrix and 18R-LPSO phase. The grain size of α-Mg in the as-cast Mg97Y1Er1Ni1 alloy is the smallest and the volume fraction of LPSO phase is the highest among all the three alloys. Moreover, the as-cast Mg97Y1Er1Ni1 alloy presents the finest particles of LPSO phase and they also distribute much uniformly. Therefore, the as-cast Mg97Y1Er1Ni1 alloy shows the best tensile properties. After solid solution treatment at 520℃ for 12 h, the three alloys Mg97Y1.5-Er0.5Ni1, Mg97Y1Er1Ni1 and Mg97Y0.5Er1.5Ni1 all consist mainly of α-Mg matrix and 18R-LPSO phase. Inside the grains of the solution-treated Mg97Y1.5Er0.5Ni1 alloy, it is found that there are some stacking faults, which does not have a complete periodicity. The tensile properties of the three solution-treated alloys are all enhanced compared with those of the as-cast alloys.

Carbon-based coatings, similar to diamond-like film, have lower friction, good corrosion resistance, and other excellent properties, which can be used as protective layers in wide fields. A high adhesive strength of the coating or film on the substrate is the critical requirement for application. However, it is impossible to grow carbon-based layers directly on the most of metals like copper, because they have a high mismatch interface. Based on the former researches and the references, the carbon-based complex coatings with three different structures were designed and grown by pulsed laser deposition. Diamond-like carbon and silicon carbide, the carbon-based materials, were deposited as the functional layer and buffer layer respectively, to make composite coatings. The interface with the weakest bonding force in the designed carbon-based complex coating was found by analyzing the micro-structure of the failure interface in the peeling coating samples. The results of comparative experiments indented that the silicon carbide layer, which played a key role in enhancing the adhesive property of the carbon-based complex coating grown at the room temperature on the metal copper substrate, could increase the bonding force of the interface between the diamond-like carbon functional layer and the metal titanium transition layer, and reduce the invalid problem of the complex coating due to the inner-stress accumulation in the thick diamond-like carbon film. The carbon-based coating of excellent adhesion could successively be prepared on the metal copper substrate, and the products can pass the relative tests regulated in the subsections ‘3.4.1.1 adhesive force’ and ‘3.4.1.3 moderate friction’ in the national military standard of ‘general specifications for optical films (GJB 2485-95)’. Nano-hardness of the coating on the copper substrate increased by 4 times compared with the bare copper, which enhanced the anti-scratch performance.

The titanium/steel composite pipe was prepared by hot extrusion at 1000℃ with low carbon steel Q235 as inner pipe and commercial pure titanium TA2 as cladding. The effect of interface microstructure on mechanical properties of titanium/steel composite pipe was studied by using metallographic microscope, field emission scanning electron microscope, X-ray diffractometer, microhardness tester and nano-indentation technology. The results show that the outer diameter of the extruded titanium/steel composite pipe is 22 mm, the inner and outer wall thicknesses are 3 mm and 0.2 mm respectively, the interface of steel/Ti pipes is well bonded, and the main phase of the interface is α-Fe, α-Ti, TiC and Fe₂Ti, etc. The grain at the interface junction of the hot extruded Ti clad steel pipe is obviously refined, and the average grain size of the interface is 1.5 μm. The grain refinement of the Ti side of the composite is higher than that of the steel side. At the same time, under high temperature hot extrusion, the dislocation density at the bonding interface of the clad pipe increases, the grains are refined, and the microhardness is also improved. Low temperature annealing has different effects on the mechanical properties of both sides of titanium/steel composite interface, weakens the work hardening degree of titanium/steel composite pipe, improves the stiffness of interface material, and has little effect on the reaction layer formed by interface intermetallic compound.