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In this paper, chitosan and caffeic acid were used as starting materials to prepare chitosan caffeates by reflux-heating and freeze-drying. The structures of chitosan caffeates were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and potentiometric titration. At the same time, the physical properties of chitosan caffeates were tested and the hemostatic properties were evaluated. The results showed that four chitosan caffeates with different mass ratios of chitosan and caffeic acid (1:1, 1:2, 1:4, 1:6) had been successfully prepared, which enhanced the water solubility. FTIR analysis demonstrated that caffeic acid had been successfully grafted onto chitosan chains. XRD showed that the crystal form of chitosan changed to some extent and the chain had some regularity in some directions, but its crystallinity reduced. Chitosan caffeates, particularly mass ratio of 1:1, showed excellent hemostatic properties and even better than chitosan and the positive control (Yunnan Baiyao), which were expected to be developed as an effective biomaterial for hemostasis.

This study proposed the new method of preparing Mg-based composite by mixed powder Ni and Ti onto the surface of pure Mg ingot. The prepared method caused that hydrogen absorbing phase Mg2Ni and catalytic phase NiTi generated and distributed regularly. The pure Mg ingot as the center and the powder Ni and Ti as cladding material on the surface were formed and sintered, in which the temperature range of generated alloy phase Mg2Ni and NiTi was confirmed at first; according to the temperature range, the size of Mg2Ni and NiTi crystal grains at 650°C and 850°C were analyzed and compared, respectively; The size of Mg2Ni alloy phase at the surface and center was calculated by comparing the atomic radius of Ni, Ti to confirm that Mg2Ni distributed on the surface due to the atom Ti replaced the atom Ni in Mg2Ni to generate the alloy phase NiTi; the capacity of the hydrogen desorption reached 4wt% within 5min. The disadvantages that easy to chalking and difficult to activate in the conventional method were avoided and achieved the application of the multilayer composite material in hydrogen storage field.

Mg-based alloys were prepared by rapid solidification of twin roll casting (TRC) which shows that the Mg-RE alloy expressed the quasi-amorphous phased and fine crystalline phase dual-phase material. Corrosion behavior of Mg-Based alloy in 3.5% NaCl solution after 48h immersion and mechanical properties were investigated. The result show that The Mg-RE alloy strip exhibited good corrosion resistance and higher ultimate tensile strength and elongation comparing to the AZ31 alloy strips. The elongation of Mg-RE alloy strip is also high than the AZ91 and ZK61 under powder metallurgy processing. These indicate that Mg-RE alloy produced by our method has a better ductility. This may due to the special microstructure of the Mg-RE alloy forms, i.e., quasi-amorphous phase plus fine crystalline phase dual phase state.

In this study, magnesium alloy AZ31 was successfully welded with aluminum alloy 6061 by diffusion bonding method. In addition, annealing process was applied to refine micro-structure and improve mechanical property. Microstructure and elemental distribution of interface were investigated with Scanning Electron Microscope (SEM) and Electron Probe Micro Analyzer (EPMA). Furthermore, experiments on diffusion bonded specimens with the usage of Transmission Electron Microscope (TEM) were carried out. At last, tensile strength was measured. It can be obtained that the width of diffusion layers increase with the increasing annealing temperatures. Elemental distribution of specimens with annealing were more uniform than that without annealing. The intermetallic compounds in diffusion layers are Al3Mg2 and Al12Mg17, their crystal structure are respectively face-centered cubic (fcc) and body-centered cubic (bcc). What’s more, tensile strength turns to be strongest after annealing at 250°C.

In this study, Mg-based alloys were prepared by rapid solidification of twin roll casting (TRC), then microstructure and element distribution were investigated respectively with Scanning Electron Microscope (SEM) and Electron Probe Micro Analyzer (EPMA). What’s more, in order to analyze microstructure and crystal structure of Mg-based alloys, experiments on specimens with the usage of X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) were also carried out. At last, the designed Mg-Re magnesium alloy with quasi-amorphous phase plus fine crystalline phase dual phase microstructure produced with our rapid solidification of TRC process. The rapid solidification process realized with a faster casting speed and a thinner roll gap that does not need any anther additional devices and vacuum environment. EPMA results and TEM analyses show that the quasi-amorphous phase has a high concentration in Al and RE element. There are quasi-amorphous phase in the middle of Mg-Re alloy cross section surrounded by dendrites phase and normal crystals. Acknowledgement. This work was supported by Cooperative Research and Development Center for Advanced Materials (CRDAM) funded by the Institute for Materials Research (IMR), Tohoku University (Project Number 18G0042).

Magnesium alloy is honored as green engineering material for its low density, high specific strength, high specific rigidity, well cutting processing property, well electromagnetic shielding property, heat conduction and easy to recycle. In this paper, AZ31 Magnesium alloy sheet at difference thickness were prepared by symmetric and asymmetric rolling employed with six-roller mill. Microstructure of the two kinds of rolling magnesium alloy thin sheets at 0.5mm thickness were investigated. The grain distribution of AZ31magnesium alloy sheets made by asymmetry rolling at room temperature are more uniform than those made by symmetry process. The grains made by asymmetry are more tiny and the tensile strength and elongation increased obviously and the mechanical properties got better. At room temperature, value of n increased. Large value of n benefit to stamping forming. At room temperature, the value of LDR of asymmetry rolling sheets is 1.26, which was higher than symmetry rolling. So asymmetry rolling benefits to stamping forming.

Spherical LiFePO4/C precursor powders were successfully prepared by spray pyrolysis. Various types of organic compounds such as glycolic acid, malic acid, citric acid, fructose and sucrose were used as carbon sources. X-ray diffraction analysis revealed that the olivine phase was obtained by calcining over 600 °C under an argon (95%)/hydrogen (5%) atmosphere. The particles exhibited a spherical morphology with approximately 1.5 μm. LiFePO4/C cathode derived from sucrose exhibited higher rechargeable capacity and cycle stability. The rechargeable capacity of LiFePO4/C cathode was approximately 154 mAh/g at 1 C. 90% of initial discharge capacity was maintained after 100 cycles.

At present, high speed machining (HSM) features in high efficiency, high precision, high flexibility and high quality. HSM technology involves many factors, including cutting mechanisms, machining performance, tool path and other aspects. The key techniques on HSM such as linear interpolation, circular interpolation, cubic B-spline curve interpolation, non-uniform rational B-spline (NURBS) curve interpolation and their respective characteristics are paid more attention and expatiated.

Water cavitation peening (WCP) with aeration is a novel surface enhancement method. A new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration, a standard N-type almen strips of spring steel SAE 1070 was treated by WCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by X-ray diffraction method. The optimal fluxes of aeration and the optimal standoff distances were achieved.

A study of a catalyst for NOx reduction used for a diesel engine of cars is done frequently currently. In the recent studies, Ag/Al2O3 catalyst system is considered to be a candidate for practical use. The ceramics molding body (ceramics honeycomb etc.) is used as a border brim of these catalysts usually. However, there is a problem. Strength to thermal shock is low. Moreover, it is not easy to go up in the center part until the catalyst operating temperature because thermal conductivity is bad and is obstructed working of the catalyst to the first stage of the reaction for that. In this research, the Ag/Al2O3 catalyst system was coated to stainless steel (SUS304) substrate that forming it is easy and heat conduction rate is good. The aluminum nitrate was used as a binder. After the binder is dissolved in the ion exchange water, the stainless steel substrate coated Ag/Al2O3 catalyst is sintered. In order to optimize coating conditions, the heating temperature, the sintering time, the density of the binder and the amount of the coating powder addition as well as the dip coating frequency were changed, respectively.

Magnetite nanoparticles were obtained by liquid phase precipitation method in which the pH value of [FeCl2⋅4H2O], [FeCl3⋅6H2O] and [NaOH] solution were controlled. Then the magnetite nanoparticle were scattered in water solution and put in [Na2SiO3] and [HCl], the resultant of reaction SiO2 can be coated on magnetite nanoparticles surface. The morphology and magnetite properties of the coated nanoparticles were evaluated by XRD, TEM, FTIR and VSM. The SiO2 thin film with nanometer size was coated on surface of nanoparticle, so that the magnetic value is decreased with the coating thickness increasing.

Strategy and function of a new developed FEM code COSMAP(COmputer Simulation of MAterial Process) for surface hardening during of thermo-mechanical processing, including heat treatment, carbonizing and nitriding, is briefly introduced in this paper. The simulation code is developed based on the metallo-thermo-mechanical theory considering the coupled equations of diffusion, heat conduction, inelastic stresses and kinetics of phase transformation. Some examples of simulation and the experimental verification for carbonized quenching, carbonizednitrided- quenching process of a cylinder and ring as well as a gear are illustrated, and comparison of the simulated values of distortion, residual stresses and profile of induced phases with the experimental data is made with some discussions.

Mechanism of transformation plasticity (TP) is discussed from continuum mechanics viewpoint, and derivation of TP law from the unified thermo-mechanical and transformation plasticity constitutive equation. Result of identified TP coefficient for a chromium steel (JIS SCr420) by use of multi-functional testing machine is introduced as one of the material data together with other data to the simulation of a quenching process by use of newly developed code COSMAP. The simulated distribution of temperature, phases and stress/distortion are compared with the experimentally measured values to verify the accuracy.

As one of the activities carried out by our group of IMS-VHT (Virtual Heat Treatment tool for monitoring and optimising HT process), results of a benchmark project on the simulation of carburized quenching process is summarized. Several programs available for taking into account the metallo-thermo-mechanical coupling had been employed for the simulation for a cylinder, ring as well as a helical gear by use of common data of material properties and cooling characteristics. Comparison of the simulated values of distortion, residual stresses and profile of induced phases with the experimental data is made with some discussions.

Twin-roll thin strip casting process combines casting and hot rolling process into a single step; in which melt and solid states exist in the casting region, so its deformation is more complex than rolling process. In this paper, Anand’s model, a unified visco-plasticity constitutive model, was employed to simulate the highly nonlinear behavior in the twin-roll casting process. Anand model’s parameters were regressed based on compression tests at various temperature and strain rate for magnesium alloy AZ31. To calculate the thermal mechanical stresses, the thermal flow of twin-roll casting process was simulated firstly; then stresses were calculate, in which the temperature field result of thermal flow was imposed as body load, and a small displacement load along roller tangential direction was imposed simultaneously in order to simulate rolling action. The deformation results can well describe the forward slip zone, backward slip zone and melt eddy zone in the casting region. Based on the results, the applicability of Anand’s model on twin-roll casting process was discussed.

Low temperature sintering NiCuZn ferrite was employed at most cases due to its co-firability with Ag (below 960°C). The purpose of this study is to fabricate NiCuZn ferrite sintered body with high-strength and high-frequency magnetic properties. Following is the procedure: firstly, NiCuZn ferrite powder was synthesized under CO2 atmosphere at 500°C from the mixed doxalate synthesized by liquid phase deposition method; then a small amount of boric acid [H3BO3] was added to the powder, and the NiCuZn ferrite powder compact was prepared with Newton press and CIP methods; finally, NiCuZn ferrite sintered body was fabricated by sintering at 900°C under CO2 atmosphere. By this method, NiCuZn ferrite sintered body with 0.5 mass% boric acid was obtained, which was additive with strength 340 MPa, high frequency applied scope below 20MHz and initial permeability 38.

An experimental study of high pressure water jet peening treatment on SPA-H and SPCC steel was conducted to study the effects of cavitation impacts of high-speed water on fatigue crack initiation and propagation of notched specimens. Pull-pull fatigue tests’ condition was 350 MPa maximum stress amplitude, 0.1 stress ratio and 10Hz frequency, while in-situ observation by SEM was employed. It was found that fatigue life of water jet peening treated SPA-H specimens has been obviously elongated by comparison with specimens without this treatment. However, for SPCC steel specimens, by comparison with those without water jet peening treatment, fatigue life was a little elongated, almost the same and obviously shortened corresponding to water jet peening treatment time of 5, 10 and 15 minute, respectively. High pressure water jet caused surface corrosion for SPCC low carbon steel, while with almost the same carbon content, copper, chromium and nickel elements increased anti-corrosion properties of SPA-H steel. These resulted in the different fatigue life of SPA-H and SPCC steel. In-situ observation on the crack tips approved above analysis.

In order to improve the durability of Pt coated Ti electrodes as an anode of the sulfuric acid system electrolysis, tantalum oxide (Ta2O5) additions have been used widely. However that is not enough for uses under severe conditions. In this study,boric acid (H3BO3) was added into the Pt coating during manufacturing process of Ti/Pt-coated electrodes, and the (Pt + B2O3)/Ti electrodes were obtained. The effect of H3BO3 addition on the microstructure, surface area, and lifetime of (Pt + B2O3)/Ti electrodes was also investigated in detail. Commercially available titanium plates (10 100.5mm) were employed for prepare Ti/ (Pt + B2O3) electrodes, where it was confirmed by XRD that B2O3 formed by heating the boric acid was amorphous in the temperature range of 250 to 550. The coating solution of 2 μl of H2PtCl66H2O (Pt:50 g/l) dissolved in butanol and 5~20 mass% H3BO3 mixture was spread over the etched Ti plates. After drying at 70 for 30 min, the substances were heated at 250 to 550 for 10 min. The lifetime of the electrodes was examined by a direct current of 1 A using Pt plate as the counter electrode in 1 M H2SO4 solution at 40. The end of life was determined as the time when the cell voltage changed 2 times of the beginning.

Magnetite (Fe3O4) ferrite magnetic materials have attracted attention arising by the chip coil electronic material. However, its industrial applications have been limited by the need for high temperature sintering under reduced pressure or vacuum. In order to develop the process method of low-cost and energy saving with high-strength and high magnetism of the magnet, in this paper, a new low-temperature sintering method using CO2 gas and adding a small amount of boric acid (H3BO3) is proposed. Here, the super fine magnetite powder was fabricated by decomposition from ferrous oxalate at 500 in CO2 gas. The ferrous oxalate was synthesized using iron chloride and ammonium oxalate through liquid phase precipitation. The magnetite powder compact was produced by Newton press and CIP (cold isostatic press) after adding a small amount of boric acid. In this study, the effects of the additive on the mechanical and magnetic properties of the sintered magnet were also evaluated. By characteristic evaluation of the magnet, the validity of the proposed new low-temperature sintering process and the optimal process conditions were confirmed.

Because of the raw material elements and its purity and so on, the Nd-Fe-B permanent magnet, the strongest magnetic material, which needs artificial synthesis, can hardly be used directly. The performance of the permanent magnet has not yet been greatly developed owing to the limitation of the artificial synthesizing technology, of the powder sintering technology and that of the application. In this paper, the magnetic abrasive machining method as a new application is put forward, and from this viewpoint, are discussed the performance and the processing technology of the permanent magnet and the magnetic abrasive machining method. A sintering route combining the direction heat treatment technique to increase the magnetic energy is suggested.