With the increase of the thrust-weight ratio of the aero-engine, CMC-SiC composites with low density, high strength and toughness, high thermal stability, long lifetime, good ablation resistance and oxidation resistance need to be developed to meet the requirements of the complicated and aggressive environments in the aero-engine. The characteristics, fabrication methods, applications on the hot components of the abroad advanced aero-engines, the domestic research achievements and the open problems of the CMC-SiC composites were introduced. The research tendencies in the high performance fibers, parts design and fabrication, environmental barrier coatings, non-destructive testing technologies, evaluation and verification method and repairing technologies were put forward.

Decanoic-palmitic acid/SiO₂ composite phase change materials were prepared with SiO₂ as carrier material and decanoic-palmitic acid as phase change material. The effect of every factor on moisture absorbing and desorbing performance and temperature control performance of composite phase change materials was studied by uniform design and multivariate nonlinear regression. The results show that primary and secondary sequence of factors affecting performance is solution pH value> mole ratio between absolute alcohol and tetraethyl orthosilicate> mole ratio between decanoic-palmitic acid and tetraethyl orthosilicate> mole ratio between deionized water and tetraethyl orthosilicate> ultrasonic wave power. The optimized preparation plan is solution pH value 3.62, ultrasonic wave power 100W, mole ratio between deionized water and tetraethyl orthosilicate 9.67, mole ratio between absolute alcohol and tetraethyl orthosilicate 5.21, mole ratio between decanoic-palmitic acid and tetraethyl orthosilicate 0.52.

Graphene-reinforced aluminum matrix nanocomposites were successfully synthesized through ball milling and powder metallurgy. The tensile strength and yield strength of graphene-reinforced aluminum matrix nanocomposites are remarkably enhanced by adding graphene nanoflakes(GNFs). Importantly, the ductility properties are remained excellently, which is firstly found in the second phase reinforced metal matrix nanocomposites. The microstructures were observed by OM, SEM and TEM method. And the tensile properties were tested.The results show that graphene nanoflakes are effectively dispersed and well consolidate with aluminum matrix, however, chemical reactions are not observed. The original structured characteristics of graphene nanoflakes are preserved very well. The average tensile strength and yield strength of nanocomposite are 454MPa and 322MPa, respectively,which are 25% and 58% higher than the pristine aluminum alloy at a nanofiller mass fraction of 0.3%, while the ductility increases slightly. The relevant mechanisms of strengthening and toughening enhancement are discussed on the base of 2D and wrinkled structured properties of graphene nanoflakes.

Based on the brief review of accelerated developing status of aircraft power technology in the world, the present status and developing trend of key materials technology for aero-engine were analyzed. In accordance with the idea of "one generation of new material, one generation of new type engine", development requirements for the materials technology of the system and main parts of aero-engine were proposed. Suggestions for improving development and application level of the materials technology in China were presented from aspects of quality stability and technical maturity, investigation and verification for engineering, materials system and data, composite materials, airworthiness certificate, etc.

The application and new development trend of metal additive manufacture technique were introduced, as well as the characteristic and NDT difficulty of metal additive manufacture products. The research progress of NDT was analyzed in emphasis, including the classification of metal additive manufacture technique, the characteristics of defect and microstructure, the influence of defects on mechanical properties, the latest development of NDT methods and standards. Based on that, the key issues that will be focused were summarized at last, that is the application of new NDT methods, on-line monitoring technology, numerical simulation, measurement and characterization of stress, as well as the establishment and development of NDT standards.

Pitting behavior of 304 stainless steel in 3.5% (mass fraction) NaCl solution was investigated by dynamic potential electrochemical impedance spectroscopy (DEIS) and time scan electrochemical impedance spectroscopy (TSEIS). The results of DEIS show that metastable pits emerge at the potential (0.02V) which is more negative than the pitting potential (0.15V), and the generation and passivation of metastable pits are stochastic. The steady pitting potential which got from DEIS is negative than breakdown potential which got from dynamic potential polarization by 0.05V. The results of TSEIS indicate that pitting nucleation can happen just when the thickness of passivation film has been reduced to some extent. It reveals the characteristics of the structure of electric double layer and passivation film by analyzing element parameter of the equivalent circuit.

The current high entropy alloys' studies are most in block, powder, coating, film and other areas. There are few studies of high entropy alloys in other areas and they are lack of unified classification. According to the current high entropy alloys' research situation, The paper has focused on the classification on all kinds of high entropy alloys having been researched, introduced the selecting principle of elements, summarized the preparation methods, reviewed the research institutions, research methods and research contents of high entropy alloys, prospected the application prospect of high entropy alloys, put forward a series of scientific problems of high entropy alloys, including less research on mechanism, incomplete performance research, unsystematic thermal stability study, preparation process parameters to be optimized, lightweight high entropy alloys' design, the expansion on the research field, etc, and the solutions have been given. Those have certain guiding significance for the expansion of the application of high entropy alloys subjects in the future research direction.

Currently, the utilization efficiency of energy still remains at a low level, although the depletion of fossil fuel is appoaching. Therefore, it is of great significance to develop new materials and technologies for energy-saving and environment protection. Phase-change materials (PCM), which can absorb or release heat through inversible phase change, are very promising in the fields of heat storage and thermal management. In this paper, the characteristics and classification of PCM were introduced briefly in the first section, and then the application and development status of PCM were reviewed and analyzed detailedly. In the third part, the main problems of PCM were pointed out, and the related research work and recent research progress were analyzed and discussed. Finally, it was pointed out that optimizing material properties through new functional composite technology, designing new material system, expanding new application fields are the main development directions of phase change energy storage materials.

The properties and application status of 6000 series aluminum alloys in automotive body panel were introduced. Besides, the precipitation behavior, strengthening mechanism, texture evolution and the influence of alloying element to properties were also discussed in detail. Additionally, the conventional heat treatment and the effect of pre-aging or pre-straining to bake hardening were described. Then some current problems and research directions about 6000 series aluminum alloys for automotive body were discussed.

With waste walnut shell as raw material, biomass based porous active carbon was made by microwave oven method. The effects of microwave power, activation time and mass fraction of phosphoric acid on adsorptive property of biomass based porous active carbon in the process of physical activation of active carbon precursor were studied by response surface method and numerical simulation method, the preparation plan of biomass based porous active carbon was optimized, and the optimal biomass based porous active carbon property was characterized. The results show that three factors affect the adsorptive property of biomass based porous active carbon, but the effect of microwave power is obviously more significant than that of mass fraction of phosphoric acid, and the effect of mass fraction of phosphoric acid is more significant than that of activation time. The optimized preparation conditions are:microwave power is 746W, activation time is 11.2min and mass fraction of phosphoric acid is 85.9% in the process of physical activation of activated carbon precursor by microwave heating method. For the optimal biomass based porous active carbon, the adsorption value of iodine is 1074.57mg/g, adsorption value of methylene blue is 294.4mL/g and gain rate is 52.1%.

Based on the fact that cold spraying (CS) was increasingly attracting more and more attention from researchers worldwide, this paper made detailed summarization and discussion on fabricating composite coatings via CS according to the published literature. Firstly, the powder preparation methods prior to spraying and the effects of processing parameters on deposition of composite coatings were explored. And then, the fabrication of metal-metal, metal-ceramic, metal-intermetallics and nano-composite coatings were summarized. Eventually, the present problems and potential applications existing in composite coatings fabricated by CS were discussed.

Metamaterials, man-made materials, enable us to design our own "atoms", and thereby to create materials with unprecedented effective properties that have not yet been found in nature. Smart metamaterial is one of those that is an intelligent perceptive to the changes from external environments and simultaneously having the capability to respond to thermal and mechanical stimuli. This paper can provide a review on these smart metamaterials in perspective of science, engineering and industrial products. We divide smart metamaterials according to what they are tuning into: optical, mechanical, thermal and coupled smart metamaterials. The rest of two techniques we addressed are modelling/simulation and fabrication/gene engineering. All of these types smart materials presented here are associated with at least five fundamental research: coupled mechanism of multi-physics fields, man-made design for atom/molecular, metamaterials coupled with natural materials, tunability of metamaterials, and mechanism of sensing metamaterials. Therefore, we give a systematic overview of various potential smart metamaterials together with the upcoming challenges in the intriguing and promising research field.

Hydrophobic SiO₂-glass fibers aerogels were prepared by sol-gel process with tetraethoxysiliane (TEOS) and methyltriethoxysilane (MTES) as the silica source, glass fibers as reinforcement, followed by ambient pressure drying. The physical properties and microstructure of silica aerogels were characterized by nitrogen adsorption/desorption tests, Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis, scanning electron microscopy, high resolution transmission electron microscopy, contact angle measurement and mechanical testing. The influences of acid concentration and soaking time during pretreatment of glass fibers on the densities of SiO₂-glass fibers aerogels were investigated. The results show that when the pretreatment condition of glass fibers is soaking 0.5h at 2.5mol/L hydrochloric acid, the obtained monolithic SiO₂-glass fibers aerogels exhibit the lowest density of 0.12g·cm^-3 and pore size is in the range of 2-50nm, the water contact angle is 142°, the thermal stability temperature reaches 500℃, the compressive strength is 0.05MPa, and the elastic modulus is 0.5MPa.

Wire and arc additive manufacturing (WAAM) was investigated by tungsten inert gas arc welding method (TIG), in which φ1.2mm filler wire of aluminum alloy 5A06(Al-6Mg-Mn-Si) was selected as deposition metal. The prototyping process was conducted by a TIG power source (working in AC mode) manipulated by a four-axis linkage CNC machine. Backplate preheating temperature and arc current on deposited morphologies of single layer and multi-layer were researched. The microstructure was observed and the sample tensile strength was tested. For single layer, a criterion that describes the correlation between backplate preheating temperature and arc peak current, of which both contribute to the smoothening of the deposited layer. The results show that the layer height drops sharply from the first layer of 3.4mm and keeps at 1.7mm after the 8th layer. Fine dendrite grain and equiaxed grain are found inside a layer and coarsest columnar dendrite structure at layer boundary zone; whereas the microstructure of top region of the deposited sample changes from fine dendrite grain to equiaxed grain that turns to be the finest structure. Mechanical property of the deposited sample is isotropic, in which the tensile strength is approximately 295MPa with the elongation around 36%.

The energy crisis and environmental pollution problem is increasingly serious on a global scale, however the rapid development of photocatalytic technology brings the dawn to solve the problem, and the photocatalytic materials system as a basic element has become the focus. The photocatalytic degradation of organic pollutants in water was focused in this article, and the development status of photocatalytic technology, nine types of photocatalytic materials and their properties, mechanism of action and the application of research, as well as modification methods of the materials were summarized. Finally, it was proposed that the materials still has the problems of low solar energy utilization, low quantum yield, and insufficient photochemical stability at the current stage, nevertheless the new material system of metal-organic framework (MOF) and the modification methods of micro/nano mesoporous, multi-hole composite, Z-scheme semiconductors provide a broader space for the exploration of photocatalytic materials.

The three-dimensional (3D) woven composites have the advantages of strong structural design ability, overall near-net shape of complex components and high impact damage tolerance, and have become the focus of the development of new materials in the aerospace industry. In recent years, the structural design, micro-modelling and performance analysis of 3D woven composites have been rapidly developed and achieved substantial achievement. The development of multi-axial woven structures, fine modeling, and automated continuous production are the development trends of 3D woven composites. In this paper, the structural characteristics of typical 3D woven preforms were introduced. The quasi-static mechanical properties of 3D woven composites with different structures were discussed. The research progress of the micro-structure modelling, theoretical analysis and numerical simulation of 3D woven composite materials were reviewed. The typical applications of 3D woven composite materials in aerospace were listed, which can provide reference for the application research of 3D woven composite materials.

High strength intermediate modulus carbon fiber composites are still the main aviation composites in the world at present and for a long time to come. In recent year, based on the experience of high-strength carbon fiber composites, the industrialization technology of high strength intermediate modulus T800 grade carbon fiber have been broken through in China, and the resin matrix, prepreg and manufacturing process were analysized systematically for the high toughness composites reinforced by Chinese T800 grade carbon fiber. The impact resistance of the resin matrix composites reinforced by Chinese T800H grade carbon fiber is at the same level with that of foreign composites, and the hydrothermal resistance of high toughness epoxy resin matrix composites is better than that of foreign composites with the same CAI level. At the same time, the prepreg of Chinese T800H grade carbon fiber reinforced high toughness composites has excellent process ability, and it can meet the requirements of manual-layup, ATL and AFP. Based on the T800 grade composites, the main research goal is to improve the compression mechanical properties, elastic modulus and CAI based on BVID(barely visible impact damage) for high strength intermediate modulus carbon fiber composites in the future.

The historical evolution, the latest research progress and the related industrial status of equipment development of the three major photopolymerization-based ceramic 3D printing technologies were reviewed, i.e. stereolithography (SL), digital light processing (DLP) and two-photon polymerization (TPP). The characteristics of feedstock materials, printing process, post-treatments and final ceramic properties were summarized and discussed.Meanwhile, some of the issues and challenges such as incapability of mass production and low efficiency persist, and high-end industrial application scenarios of printed parts still need to be excavated. Therefore, new materials, new theories and new technologies regarding ceramic photopolymerization-based 3D printing should be further developed in order to seek for efficiency and application breakthroughs. Finally, it was suggested that structural-functional integral/gradient manufacturing and multi-material/multi-process comprehensive and efficient manufacturing are the important development directions of ceramic 3D printing technology in the future.

The application background and key role as well as the basic performance requirements of ceramic cores and shells used for the investment casting of superalloy hollow blade were introduced,and the future development direction of ceramic cores and shells was described. The raw materials of the ceramic cores and shells, together with the manufacture methods and their influence on the properties were reviewed respectively. The research status and existing problems of leaching technics of ceramic cores were introduced. In addition, the important influence of positioning accuracy and the consistency of ceramic cores and shells on the quality of superalloy hollow blade was evaluated.

The research of SiC_f/SiC ceramic matrix composites (CMCs) as well as their applications in aero engines has obtained rapid development recently. This is owing to the large quantity of coupon tests performed on various properties of these materials, and the establishment of corresponding databases. Here, the physical and mechanical properties of CMCs developed by SNECMA, NASA and GE were reviewed. The influence of fabrication techniques on the properties of materials were discussed with an emphasis on tensile properties. Meanwhile, the service performances of these materials were summarized, including oxidation, water vapor/oxygen environmental resistance at high temperature, fatigue and creep behaviors, resistance to thermal shock and foreign object damage, along with the mechanism of damage and failure in environments such as heating, loading, water and oxidation. At last, some suggestions about domestic further research on performances testing for SiC_f/SiC ceramic matrix composites were proposed.

The research status on theoretic models and the coupling relationships of Orowan strengthening, dislocation strengthening, load-bearing effect of the reinforcement strengthening and others strengthening are successfully described in this study for particle-reinforced metal matrix composites(MMCs) with a volume fraction lower than 14%. Some conclusions can be obtained:Orowan strengthening and dislocation strengthening stress can be enhanced by increasing volume fraction, decreasing size of reinforcement and improving homogeneous distribution of reinforcement, load-bearing strengthening stress can also be enhanced by increasing volume fraction; yield strength and ductibility of MMCs can be enhanced much more by increasing load-bearing strengthening stress and plastic deformation region and adopting the material design method of metal matrix surrounded by particles with microstructural inhomogenous distribution; grain boundary strengthening and Peierls-Nabarro stress can also affect the yield strength of MMCs as a part of matrix strengthening, solid solution strengthening can be ignored usually; there are three coupling relationships for the sum strengthening contributions:linear summation, multiplicative combination and the root of the sum of the squares. The linear summation and multiplicative combination can be applied to nanoparticle-reinforced MMCs, the linear summation is generally applicable in the case when there are few factors influencing the strength, the multiplicative combination is the most commonly used method. The root of the sum of the squares is applied to micronparticle-reinforced MMCs.

Cu(NO₃)₂·3H₂O and Ce(NO₃)₃·6H₂O were used as modifier to make Cu-Ce/TiO₂ by sol-gel method. The influences of Cu-Ce loading capacity, Cu and Ce molar ratio, sintering temperature on Cu-Ce/TiO₂ performance were explored. Then, surface morphology, particle size distribution, pore structure and optical property of Cu-Ce/TiO₂ were characterized by SEM, LPSA, BET and UV-Vis, respectively. The results show that:prepared Cu-Ce/TiO₂ shows good photocatalytic-moisture performance when Cu-Ce loading capacity is 3%, Cu and Ce molar ratio is 1:1 and sintering temperature is at 500℃. Cu-Ce/TiO₂ presents approximate sphere, with better uniformity and dispersibility and the particle size distribution is 1202.98-5364.48nm, with d₅₀ 2437.57nm. Cu-Ce/TiO₂ has pore structure, approximate to an "ink bottle" with a narrow bottleneck, with the specific surface area 105.55m²/g, hole size 0.1200-0.1246mL/g, and average pore diameter 3.44-4.02nm. Cu-Ce doping promotes to form a new energy level inside Cu-Ce/fiO₂ so as to improve the ability to capture e^- and h⁺, enhance the efficiency of photon utilization, and promote red shift of absorption sideband.

At present, ablation is still considered as one of the most effective, reliable, mature and economical thermal protection methods, which is widely used in thermal protection systems (TPS) of aerospace flight vehicles. Recent years, series of advanced lightweight ablative composites (LAC) were developed driven by major projects such as manned space flight, lunar exploration program, deep space exploration, and near space flight vehicles. Particularly, material's developing, engineering application and corresponding applied basic research of LACs filled in honeycombs and new LAC integrated ablation & insulation were emphatically introduced. Furthermore, complicated ablative mechanisms and synergistic effects of multiple thermal protection methods were explored. With the development of advanced TPS demand, multi-functionalization, compatibility and integration are the main development tendency of LAC for earth reentry or atmospheric entry aerospace flight vehicles.

In this review, different types and properties, photocatalysis and functional mechanism of ZnO-based nanocomposite were summarized. Besides, the research advances were discussed in applications of visible-light responding ZnO-based nanocomposite in fields of degradation of organic pollutants, photocatalytic hydrogen production and antibacterial agents, and the way of thinking and suggestions for further research on ZnO-based nanocomposite photocatalyst were put forward. With the developing of basic research and application, ZnO-based nanocomposite photocatalyst will be widely used in the fields of high efficiency catalyst, environmental purification, solar energy conversion and so on.

Ti-Al system intermetallics and high-temperature ceramics or ceramic matrix composites, are the two kinds of light-mass heat-resistance structural materials with high potential in aerospace applications. According to the published literatures, the research advances on their welding and joining technologies, including the material weldabilities, joint properties with different welding processes and material combinations, and the progresses of studies on the application of the welding and joining technologies were reviewed, and some comments are made on the reporting advances especially in the past two decades. It is pointed out that, development of new high-temperature-tolerance welding consumables or brazing alloys, joining of dissimilar materials, and study on joint assessment and engineering application would be mainly important research areas in future.

Stress corrosion cracking susceptibility of X80 pipeline steel was investigated in a simulated soil solution using slow strain rate tensile (SSRT) tests. The simulated soil solution was based on the chemical compositions of alkaline Gansu soil in northwest of China. The tests were conducted at different strain rates. The fracture surfaces and secondary cracks were observed using scanning electron microscopy (SEM). The results showed that strain rates had an important role on SCC of X80 steel in simulated soil solutions. Corrosion and mechanical factors have different influences during the SCC processes at different strain rates, which results in the variety of SCC. There was the highest SCC susceptibility at the strain rate of 1.0×10^-6s^-1. Combined effect of corrosion and mechanics leads to high SCC susceptibility. When the strain rates were lower than 1.0×10^-6s^-1, enough long corrosion time results in the corrosion of crack in this strain rate range. The crack propagation is restrained. Thus, slight decrease of SCC susceptibilities occurs. As the strain rates were higher than 1.0×10^-6s^-1, SCC susceptibilities were low obviously. In this high strain rates range, the mechanical factors have more effect on SCC than corrosion factors, which mainly lead to mechanical fracture of specimens.

Laser cladding of Ni-based Ni60A+x% (SiC+Ti)(mass fraction, the same below) composite powder coating on 45 steel substrate was studied by using the method of preplaced powder. The dry friction and wear experiments of different material coatings were carried out by reciprocating friction wear tester. The microstructure and worn morphology of cladding layers were observed and analyzed by using metallographic microscope, scanning electron microscope (SEM) respectively. The results show that the prepared composite coating with dispersively distributed TiC enhanced particles are obtained in-situ, the size and number of the granular TiC gradually increase with the increase of the composite powder SiC+Ti. When the composite powder SiC+Ti reaches 60%, pores and inclusions defects exist in microstructure. When the composite powder SiC+Ti reaches 48%, wear resistance of cladding coating is the best. The wear behavior of the composite coating is abrasive wear, and the mechanism is micro cutting and extrusion spalling.

Aluminum alloy is the preferred material for lightweight structure, and has broad application prospects in aerospace, transportation and ships. The additive manufacturing of aluminum alloy possesses outstanding advantages and potential on fabricating complicated three-dimensional precision structural parts. Furthermore, this method can be characterized by its high efficiency and excellent structural properties. With regard to the rapid development of the aluminum alloy additive manufacturing, the research status and latest achievements of aluminum alloy fabricated with additive manufacturing from the aspects of structure and performance, precision and quality, controlling of defects and numerical simulation, and the shortcomings of current research were summarized. Based on these, the key issues that will be focused were summarized at last, including realizing the control of the micro-structure, clarifying the forming mechanism of the stress, improving the forming accuracy, and studying the distribution law of the temperature field in the forming process.

The latest research progresses on Fe-based amorphous coatings were reviewed. The typical alloy system and the classification of Fe-based amorphous coatings were clarified. The status, progress and development of the Fe-based amorphous coatings prepared by thermal spray processing and laser cladding process were discussed. The main mechanical properties and potential applications of the Fe-based amorphous coatings were also described. Furthermore, based on the main problems mentioned above, the future development of the Fe-based amorphous coatings was discussed, including the exploitation preparation technologies of high amorphous content of the Fe-based coatings, the development of the low cost and high performance Fe-based coating alloys system, the broadening application of Fe-based amorphous coatings, and so on.

The corrosion behavior of AZ31 magnesium alloy with different Gd contents in 3.5%(mass fraction) Na₂SO₄ solution was investigated by mass loss method. The effect of rare earth Gd on microstructure, corrosion rate and corrosion morphology of AZ31 magnesium alloy was analyzed by optical microscope (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that adding rare earth Gd can improve the corrosion resistance of AZ31 magnesium alloy significantly. When the Gd content is less than 4.12%, the corrosion resistance of the alloy increases with the increase of Gd content, but when the Gd content is more than 4.12%, the corrosion resistance of the alloy declines at a certain degree with the increase of Gd content. This is mainly caused by the content of Gd, which exacerbates the micro-galvanic corrosion effect between the precipitation phase and matrix phase, and thereby results in the decline of the corrosion resistance of the alloy. So when the content of Gd is 4.12%, AZ31 magnesium alloy has the optimum corrosion resistance.

To meet the needs of large composite bonding for aircraft, development, comprehensive experimental and application of adhesive materials have been carried out. Development process, adhesive bonding performance, operability and batch production of parts of adhesives are presented in brief. Traditional metal structural adhesives are widely applied to composite bonding for military use and civil use. We have made some progresses in development of toughened cyanate film adhesive and toughened BMI film adhesive. Development of high temperature resistant adhesives such as polyimide adhesive will be an important investigation area. All kinds of adhesives with different heat-resistant and chemical compositions need to be developed to meet adhesive selections for various composite bonding.

The process technology and the mechanical and electrical properties of the "metamaterial"structural absorbing composites were studied, in which metal periodic structure units were produced on the organic carrier film and then combined with medium. Through the breakthrough of key technologies involving producing different size metal periodic structure, the transfer of metal periodic structure, and optimizing process parameters, the "metamaterial" structural absorbing composite with good wave-absorbing and mechanical stabilities that contained multi-layer metal periodic structure was prepared. The "metamaterial" structural absorbing composite has a high broadband absorbing property in the frequency range of 2-18GHz.

Diamond-like carbon (DLC) films had many unique and outstanding properties such as high thermal conductivity, high hardness, excellent chemical inertness, low friction coefficients and wear coefficients. The properties and combinations were very promising for heat sink, micro-electromechanical devices, radiation hardening, biomedical devices, automotive industry and other technical applications, more research and a lot of attention were attracted in recent years. The research progress of diamond-like films and the nucleation mechanism of film were summarized, and application prospect of DLC films were demonstrated. The aim of this paper is to provide insights on the research trend of DLC films and the industry applications.

Equal channel angular pressing (ECAP) is an interesting method for changing microstructure and producing ultra fine grained (UFG) materials through super-plastic deformation. The homogeneous deformation is the main factor that influences the material performance during ECAP. Four processing routes are analyzed in detail by using finite element method with spatial switching method through rotating three-dimensional model in multi-pass pressing. The accumulated effective strain distribution of the work-piece processed by ECAP for four pressing routes are obtained respectively through finite element simulation. The processing route that can generate more homogeneous effective's main distribution in sample after four routes processing is defined. The mechanical property of AZ31 magnesium alloy processed by multi ECAP passes in different routes was analyzed through microstructure observation and mechanical tensile test at room temperature. The experimental results show that the fine and uniform microstructure can be acquired by appropriate deformation route, the mechanical property of AZ31 magnesium alloy is greatly improved when strain accumulation uniform after ECAP processing.

Fe-Cr-B-C hardfacing alloys were deposited by flux-cored wire using metal active gas arc welding (MAG). The effect of boron contents on the microstructures and boride morphologies of the hardfacing alloys was analyzed by optical microscopy(OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate that the microstructures of Fe-12Cr-xB-0.1C alloys consist of ferrite, austenite, (Fe, Cr)₂B, and (Fe, Cr)₂₃(B, C)₆. The morphology of borides transforms from the discontinuous network to continuous network gradually with boron content increasing to 3% (mass fraction). As the boron content is higher than 3%, the amount of massive primary (Fe, Cr)₂B increases with the increasing of boron contents. Meanwhile, the size and distributing of (Fe, Cr)₂B become more homogeneous. The morphology of primary boride has many kinds of distribution shape, including massive, strip, fish-bone-like, honeycomb and chrysanthemum. The shape of the primary (Fe, Cr)₂B is quadrangular column which tends to grow perpendicular to the overlayer surfaces. Increasing boron content can significantly improve the hardness and abrasive wear resistance of Fe-Cr-B-C hardfacing alloys when the boron content is lower than 4%.

The surface properties of two domestic T800-grade sized and desized carbon fibers were characterized by scanning electron microscope(SEM), atomic force microscope(AFM) and X-ray photoelectron spectroscopy(XPS). The micro-interface shear strength(IFSS) of single fiber composites was also analysed by single fiber fragmentation test(SFFT). The influences of surface properties on micro-interphase strength of single carbon fiber composites and hygrothermal properties were investigated. The results show that the amount of surface active functional groups decreases and surface roughness increases, but the interfacial adhesion between fiber and matrix enhances after desizing. In addition, the hygrothermal environments dramatically decrease the micro-interphase strength, especially degrade the chemical bond force on the interphase, but interphase properties can partially recover after humidity desorption.

Effects of Fe and Si impurities on the microstructure and mechanical properties of 7××× series aircraft aluminum alloys are overviewed. The Fe and Si impurities mainly form coarse and insoluble intermetallic particles in the microstructure. Among a variety of iron rich intermetallics, Al₇Cu₂Fe phase is typically found in the alloys with higher Cu content while the Mg₂Si phase is the main silicon rich intermetallics. The increase of the Fe and Si contents has little effect on the strength, but markedly reduces the plasticity, fracture toughness and stress corrosion resistance of 7××× aluminum alloys in that the contents of coarse Fe-rich and Si-rich insoluble impurity phases increases.Reducing the contents of Fe and Si impurities is significant to develop the high comprehensive properties of aircraft aluminum alloys.

The CNTs/rGO/NG composite lithiumion battery anode material was synthesized by thermal reducing, using graphene oxide (GO) and carbon nanotubes (CNTs) as precursors for a 5：3 proportion. The morphology, structure, and electrochemical performance of the composite were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared spectra (FTIR) and electrochemical measurements. The results show that reduced graphene oxide and carbon nanotubes form a perfect three-dimensional network structure on the surface of natural graphite. CNTs/rGO/NG composite has good rate performance and cycle life, compared with pure natural graphite. The initial discharge capacity of designed anode is 479 mAh/g at 0.1 C, the reversible capacity up to 473 mAh/g after 100 cycles, the capacity is still 439.5 mAh/g, the capacity retention rate is 92%, and the capacity is 457, 433, 394 mAh/g at 0.5, 1, 5 C, respectively.

The hot deformation behavior of the advanced ultra-high strength hot stamping steel 22MnB5Nb was studied through the isothermal uniaxial tensile tests at 650-950℃ and strain rates of 0.1, 1.0s^-1 and 10s^-1 by Gleeble 1500D system. The conventional Arrhenius-type hyperbolic sine equation, the Arrhenius-type model considering the material constant strain compensation and the new Arrhenius-type model based on Quasi-Newton BFGS algorithm were established to describe the high-temperature deformation behavior of 22MnB5Nb. The results indicate that 22MnB5Nb steel shows typical work hardening and dynamic recovery softening behavior during hot tensile. And the strain rate and deformation temperature have significant effects on the flow stress. The peak flow stress values predicted by these models are highly consistent with the experimental values, and the Quasi-Newton BFGS algorithm can solve all the material parameters in one time and it is simpler in calculation process and has the highest accurate(R=0.99578, R_e=11.03MPa, E=2.48%), while, the Arrhenius-type model considering material constant strain compensation with lower accuracy, but can directly predicts not only the flow stress curve under different deformation conditions, but also the work hardening behavior, the dynamic recovery behavior and the strain rate strengthening effect of the experimental steel during the deformation process.

For conventional A356 aluminum alloy, the addition of rare earth elements is an effective way to modify its microstructures and improve its mechanical properties.The effect of rare earth Er on microstructures and properties of as-cast A356 aluminum alloy was studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM).The results indicate that rare earth element Er is a good modifier for A356 aluminum alloy, which is able to improve obviously the microstructure of as-cast alloy.The addition of Er refines the primary α-Al phase, decreases the secondary dendrite arm spacing and the dendrite arm diameter, and modifies the eutectic Si in as-cast structure simultaneously.When the amount of Er reaches 0.4% (mass fraction, the same below), the refinement effect is the most significant, secondary dendrite arm spacing decreases from 53.6μm to 17.5μm and the morphology of eutectic Si transforms from thick lath-shaped to short rod-like or round granular.Compared with A356 alloy, the tensile strength and elongation of A356 aluminum alloy with the addition of 0.4%Er increase by 15.1% and 29.8% respectively.