The microstructures of the cold-swaged and recrystallized Ti-23Nb-0.7Ta-2Zr-O (TNTZO) (mole fraction, %) alloy were investigated by electron backscatter diffraction (EBSD). The difference in microstructure, texture and recrystallization process was evaluated between the TNTZO alloy and traditional body centered cubic (bcc) metals. The results show that the cold-swaged TNTZO alloy presents a pronounced  110  fiber texture in the axial direction. The recrystallization of the TNTZO alloy is achieved by the nucleation of new grains and the growth of these new grains at the expense of the deformed structure. The TNTZO alloy behaves a very similar way to traditional bcc metals in the features of the microstructure, texture and recrystallization.

MoSi₂ was prepared by SHS, pressed at room-temperature and then vacuum sintered at 1 500 ℃ for 1 h. The tribological properties of MoSi₂ against Al₂O₃ were investigated by using an XP-5 type High Temperature Friction and Wear Tester. Micrographs and phases of the worn surface of MoSi₂ were observed by SEM with EDS and X-ray diffraction. The results show that the wearing process of MoSi₂ at high temperature exists three stages: running-in, interim and steady periods. MoSi₂ exhibits preferable wear resistance when the load is lower than 50 N. Adhesion and oxidation wear exists widely at elevated temperature; however besides these, with increasing the load, the main wear mechanisms of MoSi₂ could be changed from adhesion, plastic forming to fatigue fracture in turn.

Based on the time-dependent Ginzburg-Landau (TDGL) equation, the temporal evolution of the domain structure and hysteresis loops of polarization versus electric field were simulated by a phase-field model for Bi₄Ti₃O₁₂ (BIT) ferroelectric single crystal under an applied electric field. In the static electric energy induced by an applied alternating electric field, the effects of field frequency on the ferroelectric properties of BIT ferroelectrics were investigated. The results show that the evolution of ferroelectric domain structure is a gradual process including domain nucleation, domain wall motion, domain growth and domain combination. In the boundary regions of ferroelectric domain, the new domain nucleations occur and the old domains disappear. The coercive field increases with the field frequency, and it is in good agreement with the previous experiment.

A nanocrystalline layer was produced on the surface of Ni₃Al intermetallic by means of surface mechanical attrition treatment. The surface nanocrystallites were annealed at 250−750 ℃ for 30 min. Microstructure evolution of nanocrystallites during annealing was studied by X-ray diffraction (XRD) and transmission electronic microscope (TEM). The experimental results show that long-rang order recovers rapidly when annealing temperature is below 250 ℃ and changes slowly at 350−550 ℃, and then it increases rapidly at 750 ℃. The grain size of nanocrystallites of Ni₃Al keeps stable and crystal defects recover when they are annealed below 550 ℃. The grains grow normally in low temperature annealing and abnormal growth occurs at 750 ℃.

The microstructure and magnetic properties of cold rolled non-oriented electrical steel, annealed at 200−1 000 ℃ for 0−240 min with different heating rates, were investigated by optical microscopy, scanning electron microscopy, Epstein frame, and transmission electron microscopy. The results show that the magnetic properties of cold rolled non-oriented electrical steel can be improved by controlling the annealing process to obtain uniform coarse grains with critical sizes after the recovery, recrystallization and growth of grains. Additionally, the annealing temperature influences the magnetic properties more significantly than annealing time, and with the increase of heating-up rate during the annealing process, the magnetic properties of the cold rolled non-oriented electrical steel increase.

The HIP diffusion bonding of P/M titanium alloy Ti-6Al-4V and stainless steel 1Cr18Ni9Ti using pure Ni as intermediate layer was studied. Bonding joint with complex bonding interface was obtained by HIPing pre-alloyed Ti-6Al-4V powders and stainless steel 1Cr18Ni9Ti in a vacuum canning. The joint strengths were examined and the characteristics of bonding joint were observed. The result shows that the maximized strength of HIP diffusion bonding between P/M titanium alloy Ti-6Al-4V and stainless steel 1Cr18Ni9Ti can be up to 388 MPa and the microstructure of bonding joint is acceptable.

The corrosion resistance and mechanical properties were tested and compared for the newly synthesized as-cast, as-solution Ni-Cr-Mo-Cu corrosion resistant alloys and 1Cr18Ni9Ti austenitic stainless steel. Their valence electron structural units were constructed, and the relative parameters were calculated by means of the Empirical Electron theory of Solids and Molecules (EET). The results show that, during alloy elements Cr, Mo and Cu entering Ni-matrix, the bonding strength n_A and bonding energy E_A of the strongest bond of the alloy are greatly increased, causing the stronger solid solution strengthening effects (about 30% increase in σ_b). Also, as reinforcement of the main bond network and the improvement of stability of the alloy system due to the solution of these alloying elements in γ-Ni, the ionization of metal atoms in corrosion solution and the flow of electrons from anode to cathode would all be impeded during electro-chemical corrosion processes, which leads to the excellent corrosion resistant ability of the present Ni-Cr-Mo-Cu alloy (about 2-3 orders of magnitude as high as 1Cr18Ni9Ti austenitic stainless steel) in several highly aggressive solutions.

The aging characteristics including microstructures and properties were investigated for a new metastable beta titanium alloy named Ti-B20 subjected to different solution treatments. Microstructural examination shows that precipitate-free zones, which are present in the many metastable beta titanium alloys, are not produced in the aged new alloy. The decrease of yield stress with the increase of aging temperature is due to the coarsening of alpha platelet. Furthermore, the age hardening effect of the new alloy strengthens with the increase of solution treatment temperature. These aging characteristics are attributed to the relatively lower concentration of beta stabilizer in the new alloy.

The impact toughness of TC21 alloy after different types of forging and heat treatments was studied. The results show that heat treatment at 915 ℃ for 1 h followed by air-cooling can achieve the highest impact toughness. The crack propagation path of bimodal microstructure is different from that of lamellar microstructure. Boundaries of primary α grain are observed to be preferential sites for microcrack nucleation. With the increase of heat treatment temperature, the volume fraction of primary α phase decreases and the nucleation sites of microcrack at the primary α phase boundaries also decrease, the impact toughness value is effectively improved. The microcracks of lamellar microstructure are located on α/β interface, or the boundary of colony, and/or grain boundary α phase. The crack propagates cross the colony, or along the colony boundary, and/or along β grain boundary. The crack propagation path of lamellar microstructure is dependent on the size, direction of colony. The crack path deflects at grain boundaries, colony boundaries, or arrests and deviates at α/β interface because of crisscross α lamellar. Therefore the impact toughness value of basket microstructure is higher than that of Widmanstatten microstructure.

Nickel-based graphite-containing composites were prepared by powder metallurgy method. The effect of graphite addition on mechanical properties of nickel-based alloy was investigated and the tribological properties from room temperature to 600 ℃ were tested by a pin-on-disk tribometer with alumina, silicon nitride and nickel-based alloy as counterfaces. The microstructure was analyzed by X-ray diffraction(XRD) and scanning electron microscope (SEM) attached with energy dispersive spectroscopy(EDS). The worn surfaces at high temperature were observed by optical microscope and SEM. The results show that the tensile strength and hardness of composites decrease after adding graphite, while the friction and wear properties are all improved by adding 12%(mass fraction) graphite. Compared with the counterface of alumina and silicon nitride, the friction coefficients and wear rates are lower when the composite rubs against nickel-based alloy containing molybdenum disulfide.

Ni-20Cr powders mixed with tungsten, aluminum, titanium, and different contents of molybdenum disulfides were hot-pressed in graphite mould by powder metallurgy method. Their tribological properties from room temperature to 600 ℃ and mechanical properties at atmosphere were tested. The results show that the hardness and anti-bending strength of composites increase  by more than 20% when containing 6%(mass fraction) MoS₂. But when molybdenum disulfide content exceeds 6%, the hardness and anti-bending strength will decrease gradually. The addition of MoS₂ is favored to the reduction of friction coefficient of composite. The friction coefficient of composite decreases with the increase of molybdenum disulfide until the percentage of lubricant reaches 12%. In excess of this value, the friction coefficient value starts to ascend. The wear rates of composite with molybdenum disulfide are one order of magnitude lower than the alloy without lubricant. When the addition amount of MoS₂ is in the range of 6% and 12%, the wear rates keep at the resemble level.

The nature of magnetic and electronic structure in double perovskite structure A₂FeMoO₆ (A = Sr, a, Ca) was calculated using the local spin density approximation (LSDA) and the LSDA+U Coulomb interaction method of density functional theory. The result shows that Sr₂FeMoO₆ is magnetic metallic material, whereas Ba₂FeMoO₆ and Ca₂FeMoO₆ are half-metallic materials. Fe has great effect on the magnetic property of double perovskite structure A₂FeMoO₆ materials. Because of the orbit hybridization and polarization between the metal element and O element, the Mo element has magnetic properties. The static magnetic moment of double perovskite structure A₂FeMoO₆ materials, the value of the magnetic moment of these A₂FeMoO₆ for (A＝Ca, Sr, Ba) are 3.626 43μ_B, 2.678 64μ_B, 3.706 17μ_B, respectively. The magnetic moment of Fe element in the crystal cell are, 3.626 43μ_B, 2.678 64 μ_B, 3.706 17μ_B. And the energy of crystal cells are −28 540.561 907Ry, −24 268.037 272Ry, −44 106.187 179Ry. These values are in agreement with the experiment values.

Aluminum matrix composites reinforced with carbon nanotube were fabricated by a powder metallurgy method. The effects of carbon nanotube content on the relative density, the hardness, and the friction and wear behavior of the composites under dry sliding condition were investigated using the ball (pin)-on-block tester. By scanning electron microscopy (SEM), the worn surfaces and worn chips were observed, and the wear mechanism of composites was analyzed and discussed. The results indicate that the addition to the aluminum matrix of 2.0%(mass fraction) carbon nanotube causes the increase in the Vickers hardness of about 80%. Within the range of carbon nanotubes content from 1.0% to 2.0%, both the friction coefficient and wear rate of composites decrease with the increase of carbon nanotube content. The delamination wear is the main wear mechanism for the composites.

The effects of the initial condition of synthesis on electrochemical properties of Li₄Ti₅O₁₂ were studied with the comparison among starting and final materials by SEM, XRD and electrochemical analysis methods. The influence of the solvents for mixing the starting material on the products was investigated. The results show that nano-sized Li₄Ti₅O₁₂ powder obtained by nano-sized TiO₂ with ethanolamine as solvent shows more excellent electrochemical performance. More than 95%, 91%, 85% and 71% of the nominal capacity is achieved respectively at 0.5C, 1C, 2C and 4C rate without excellent capacity fading after more than 30 cycles.

The Zn-Mg alloys with Mg additions of 35%, 40% and 45%(mass fraction) were prepared by conventional casting method, with the aim to develop new biodegradable materials. The effects of cooling rate and composition on the microstructures, hardness and corrosion resistance were studied by XRD, SEM, microhardness and corrosion testing techniques. The corrosion behaviors of experimental alloys in simulated body fluids were analyzed. The results show that the amount of the petal-like MgZn₂ phase decreases, as well as the hardness of the alloys, but that of the polygonal MgZn₂ phase increases with the increase of Mg content when the cooling rate is constant. When the alloy composition is constant, the MgZn₂ phase changes easily from petal-like to polygon, and the hardness decreases with the decrease of the cooling rate.

Nb/304L stainless steel composite plate was fabricated by explosive welding. Microstructure and content distribution along the interfaces of composite were studied by optical microscope (OM), scanning electron microscope (SEM) and energy spectrum (EDS). The results show that the waveform bonding can be obtained when proper dynamic parameters of explosive cladding are subjected. The interfaces undergo severe plastic deformation, which leads to the increase of hardness. There exist molten regions on both sides of wave peak and molten layers in bonding interfaces. And there is no obvious element diffusion on the both sides of bonding interface.

CO₂ emission levels of copper and zinc mines from which Japanese smelters import ore concentrates into Japan, were estimated by using a database called MLED. Eleven copper mines selected from data availability of mine site covered 84% of the total imported concentrates. Adding inventories of sea transportation and smelting processes to mine development process, total CO₂ emission level for copper and zinc ingots produced in Japan were calculated. The results show that the emission share of mining and mineral processing processes for each mine is indicated around 30%−70% of total emission for ingots, which implies the importance of including the mining activities to the inventory of upper stream products.