Hot pressed Al-based composites of 15% SiC/2009A1 (volume fraction) were prepared by powder metallurgy method. The effect of the variation of Al powder sizes (13 μm, 32 μm) and temperatures (560^oC, 580^oC, 600^oC) on their microstructure and mechanical property was studied using optical microscopy (OM), scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and tensile tests. The results show that the composite prepared with small Al powders has higher strength and ductility than that prepared with large Al powders. The reason could be attributed to the following three aspects. First, large Al powders result in the uneven distribution of SiC particles in the matrix. Secondly, in the composites prepared with large Al powders, Cu and Mg spread unevenly and which then react with the extrinsic contaminants such as Fe and O, forming large-sized insoluble phases. Thirdly, in the composite prepared with large Al powders, the bonding between SiC particles and the aluminum matrix is weak, which is particularly obvious when the hot pressing temperature is low, resulting in debonding of SiC-Al interface during tensile tests. The fracture mechanism of the composites prepared with the two Al powders was analyzed. At all hot-pressing temperatures, the composites prepared with small Al powders are fractured due to the tearing of the Al-matrix and fracture of SiC partculates. However, for the composite prepared with large Al powders, SiC particles and aluminum matrix tend to debond when hot pressing at low temperature, while the interfacial bonding is improved with the increase of hot pressing temperature. When hot pressing at 580^oC, the mechanical properties of the composites are the best, especially for that withsmall Al powders. Correspondingly, the tensile strength and yield strength reach 556 MPa and 381 MPa respectively, and the elongation reaches 9.2%.

Hexagonal boron nitride (h-BN) is a typical layered structure material with enormous potential in the field of friction and lubrication. Fluorinated boron nitride nanosheets (F-BNNSs) were prepared by constant temperature magnetic stirring and ball mill-assisted fluorination using NH₄F as fluorine sourced, while h-BN as raw material. Tribological behavior of hexagonal boron nitride nanosheets (h-BNNSs) and F-BNNSs as water-based lubricant additives were evaluated under Ti6-Al-4V(TC4)/GCr15 contact conditions. The results showed that when as water based liblicant additives, the F-BNNSs prepared with the mass ratio of h-BN to NH₄F increased from 1:2 to 1:4, the resulted average coefficients of friction (COFs) varied from 0.3135 to 0.1435 to 0.2177. When the mass ratio of h-BN and NH₄F was 1:3, the COFs and wear rate of F-BNNSs₁₂ prepared were 55% and 75% lower than that of h-BNNSs, respectively. Based on the analysis of wear scars, it were found that the excellent friction reduction and anti-wear performance of F-BNNSs₁₂ can be attributed to three aspects: The weakening polar interactions between the nanosheet layers may facilitate the relative slidding; F-BNNSs₁₂ incommensurate nanorod-nanosheet structure may cause rolling friction and good lubrication performance; F-BNNSs₁₂ deposited on the surface of the friction pair favour forminga discontinuous lubricating film, to alleviate the direct contact for the friction pair.

A highly active and stable visible light photocatalyst of composite ZnNiAl-LDH/Cu₂O was successfully prepared by using co-precipitation method to depositing two-dimensional layered ZnNiAl-ZnNiAl-LDH on Cu₂O particles. The photocatalytic activity of the prepared composite catalyst was evaluated by the degradation of tetracycline (TC) under visible light. It is found that the developed ZnNiAl-LDH/Cu₂O exhibited higher activity than the pure Cu₂O, while the ZnNiAl-LDH/Cu₂O photocatalyst doped with 7% of ZnNiAl-LDH exhibited the highest photodegradation activity, by which 89.6% of TC was decomposed within 50 minutes. The ZnNiAl-LDH/Cu₂O photocatalyst present considerably high photocatalytic degradation activities on TC. The high photodegradation efficiency of 7%ZnNiAl-LDH/Cu₂O could be ascribed to the efficient interfacial charge transfer at the composite and the synergistic effect between Cu₂O and ZnNiAl-LDH, which resulted in the enhanced separation efficiency of photogenerated electron-hole pairs.

One-dimensional carbon nanotubes (CNTs) have made them candidate as lightweight broadband microwave absorption material due to their intrinsic high electrical conductivity, light weight, and high specific surface area etc. In this paper, heterostructures of magnetic particels of iron oxide encapsulated with nitrogen-doped carbon nanotubes (Fe₃O₄@NCNTs) have been successfully constructed in-situ by one-step pyrolysis process. The phase composition and structure of the composites were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The electromagnetic parameters were measured by coaxial method and the reflection loss was simulated by Matlab. The results show that the calcination temperatures and the raw material ratio have important effect on the microwave absorption properties of nitrogen-doped magnetic functionalized carbon nanotube composites. The results demonstrated that when the calcination temperature was 750^oC and the raw material ratio (metal salt/carbon source) is 2:1, the Fe₃O₄@NCNTs-750 hybrids with only 10% of functional fillers reached a minimum reflection loss value of -57.7 dB and a maximum effective absorption bandwidth (EAB, below -10 dB) of 6.4 GHz at 2.0 mm.

Tungsten (W) is considered as one of the most promising plasma facing materials for fusion devices due to its excellent properties such as high melting point, high thermal conductivity, high sputtering threshold and low hydrogen isotope retention. In this study, high-purity tungsten blocks are irradiated by helium (He) ions at temperatures > 2000 K, and the effect of changes in irradiation parameters on the evolution of the W surface morphology is investigated. The results show that at 2300 K, the surface of the W samples shows a significant swelling morphology due to the growth of helium bubbles. As the ion fluence increases, the helium bubbles rupture, accompanied by the appearance of surface holes, and further surface swelling gradually develops into cross-linked coral-like tungsten nanofilament structures; With the increase of ion energy, the depth of helium ions injected into the W material increases, which promotes the growth of surface tungsten filament-like structures. When the temperature is changed from 2100 K to 2400 K, the temperature increase enhances the rapid diffusion of self-interstitial tungsten atoms on the surface, which leads to the suppression of the surface swelling and tungsten filament-like structure growth behavior, and even the degradation of the tungsten filament-like structure. The increase in both helium ion fluence and ion energy promotes the formation and evolution of tungsten filament-like structures on the surface of W materials after high-temperature He ion irradiation in the adopted range of experimental parameters, while the increase in temperature shows the opposite trend.

Hot-dip galvanized dual-phase steel DP980 samples were prepared by adhesive method, and their cross-sections were characterized by TEM. The interface layer structure and zinc coating structure were characterized by TEM combined with SAED and EDS. Then spatial morphology and composition distribution of the interfacial layer and galvanized layer was figured. The results indicated that unlike DP780, which mainly undergoes external oxidation of Mn during the annealing stage, DP980 mainly undergoes internal oxidation. Due to the presence of Cr, its oxidation competes with that of Mn. Less MnO in the interface layer may facilitate the Fe-Al reaction in the hot galvanizing process, forming a continuous and dense Fe₂Al₅ inhibiting layer, which can effectively inhibit the Fe-Zn reaction in the galvanizing stage. This is the main reason why DP980 has good hot dip galvanizing performance. In addition, this structure leads to the formation of Fe₃Zn₁₀ nanocrystals dispersed in the η-Zn matrix. This can avoid the formation of a galvanized layer structure containing large size of brittle Fe-Zn phase, which is beneficial for DP980 to maintain good mechanical properties.

A novel composite hollow FeS₂/NiS₂/Ni₃S₂@NC cube is synthesized through collaborative etch-precipitation (CEP) route, high-temperature calcination, polydopamine coating and high-temperature vulcanization with a pre-prepared Cu₂O cube as sacrificial template. The preparation process is safe, while Ni and Fe are successfully incorporated through the CEP route. The hollow cube structure can effectively restrain the volume expansion and slow down the mechanical stress caused by lithium-ion embedding and release. The introduction of N-doped carbon layer (NC) can greatly improve the conductivity and structural stability of the composite material, so that it can better maintain the stability of the cube structure. Furthermore, after 100 cycles at a current density of 0.2 A·g^-1, the specific discharge capacity of the FeS₂/NiS₂/Ni₃S₂@NC cube composite can be maintained at 899.4 mAh·g^-1, showing high specific capacity, good cycle stability, and great rate performance (427.5 mAh·g^-1 at 3.0 A·g^-1).

Ceramic materials (Y_0.4Er_0.6)₃(Al_{1 - y} Mn _y )₅O₁₂ (y = 0, 0.02, 0.04, 0.06, 0.08, 0.1) were prepared by solid phase synthesis method, and their microstructure and thermal conductivity were studied by X-ray diffractometer and Rietveld refinement method, X-ray photoelectron spectroscopy, scanning electron microscopy, X-ray energy spectroscopy, transmission electron microscopy, laser thermal conductivity tester. The results show that the ceramic materials of (Y_0.4Er_0.6)₃(Al_{1 - y} Mn _y )₅O₁₂ are all single YAG phase, with the increase of Mn doping, the lattice constant and cell volume decrease and then increase, Mn²⁺ gradually occupies the position of Al³⁺ in the cell, keeping the crystal structure of Y₃Al₅O₁₂ unchanged; the thermal conductivity of the ceramic material (Y_0.4Er_0.6)₃(Al_{1 - y} Mn _y )₅O₁₂ is significantly reduced, with the lowest thermal conductivity at Mn doping y = 0.06, which is about 1.38 W/(m·K) at 1100^oC, and reduced by about 34.6 % compared to that of the pure ceramic material YAG (2.1 W/(m·K)).

Fiberglass based porous ceramics were prepared via foam-gelcasting process using 48.75% (mass fraction) fiberglass and 16.25% (mass fraction) glass particles as main raw materials, 0.25% (mass fraction) Isobam-104 as dispersant, 0.1% (mass fraction) sodium carboxymethyl cellulose as foam stabilizer, 0.6% (mass fraction) sodium dodecyl sulfate as foaming agent, and gadolinium oxide as neutron shielding agent. The effects of heat treatment temperature on the phase composition, microstructure, pore structure, linear shrinkage, flexural strength, compressive strength, thermal conductivity of and porosity of the porous ceramics, and the effect of gadolinium oxide content on the physical properties, microstructure, neutron shielding performance and thermal conductivity of the porous ceramic composites were investigated. The results show that the heat treatment temperature had a great influence on the microstructure and mechanical properties of the porous ceramics. As the temperature increased from 700^oC to 800^oC, the size and the number of pores (open pores and window pores) decreased gradually, the pore walls became thick and dense, the flexural and compressive strength of the porous ceramics increased from 0.3 MPa and 0.75 MPa to 5.1 MPa and 10.7 MPa, respectively, while the thermal conductivity increased from 0.075 W/(m·K) to 0.28 W/(m·K). After being treated at 750^oC, the physical properties of porous ceramics were excellent, namely the flexural strength, compressive strength and porosity were 1.4 MPa, 2.1 MPa, 79.8% (mass fraction) respectively and the thermal conductivity was as low as 0.11 W/(m·K). With the increase of gadolinium oxide content from 0 to 6% (mass fraction), the porosity and mechanical properties of porous ceramic composites decrease, but their neutron shielding properties are significantly improved. When added 6.0% (mass fraction) gadolinium oxide, the neutron shielding rate and the thermal neutron shielding rate of the as-prepared porous ceramics were 50.8% and 82.9% (mass fraction) respectively, but the thermal conductivity was still 0.11 W/(m·K). Compared with traditional shielding materials, the glass fiber based insulating porous ceramic composite prepared in this work has excellent mechanical properties, as well as excellent thermal insulation and neutron shielding properties.