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The inertial friction welding of similar PM FGH96 superalloy was investigated. The inertial friction welding introduced steep thermal gradients of welding zone for PM FGH96 superalloy, the whole welding process only needed several seconds, therefore, it’s a fast heating and cooling completely recrystallization process. Dramatic changes in the microstructure were observed over a narrow weld zone, which across the weld interface was measured to be about 1.0-1.2mm. Significant changes in the secondary and tertiary γ′ distribution can be observed over the first 2mm from welding line, while very fine tertiary γ′ particles precipitated in a unimodal size distribution and in a high density at welding line. The fine secondary re-precipitated γ′ under fast cooling was spherical in shape, which gradually transformed into elliptical, cube with the distance from welding line. No significant texture or grain distortion was observed in the extensively plastically deformed region due to recrystallization.

Secondary electron emission (SEE) processes play an essential role in spacecraft surface charging. It is difficult to study SEE of insulator whose surface cumulates charges by incident electron bombardment because of poor conductivity. This paper investigated the theoretical process of generation, transfer and escape of secondary electrons, and finally the paper presented a mathematical model to calculate the secondary electron emission. We also have improved measurement system to measure total SEE coefficient from dielectric with 1-5 keV electron irradiation which is perfectly fit to mathematical model, and the SEE coefficient with different surface charging is investigated. The results indicate the SEE coefficient decreases with positive charging and increase with negative charging of dielectric surface.

Linear defect is a common defect of galvanized sheet. Formation mechanism of linear defect was analyzed by scanning electron microscopy (SEM) and energy disperses spectroscopy (EDS). The results indicate that Al2O3 particles which have a size less than 7μm are enriched in the shallow surface of the substrate. Al2O3 particles are exposed during rolling, resulting in scratches and rough spots on cold-rolled sheet. The places where Al2O3 inclusions enrich are easy to form surface micro-cracks. Linear defects are formed at the places of scratches or cracks during hot dip galvanizing. Optimum measures are putted forward based on Al2O3 inclusions and cracks.

The blade is one of the key part of aero engine because its shape precision and surface quality significantly influence the performance, efficiency and reliability of the engine. The blade surface is generally obtained by precision finishing process, which is a repeated work of profile error measurement, profile error calculation and error correction manufacturing. For profile error calculation, the matching of measurement points and ideal blade surface must be firstly performed. However there is few detailed work reported on matching algorithm. In this paper, a new matching algorithm for profile error calculation was proposed. Firstly, the coarse matching method based on characteristics of blade section curves between measurement points and its corresponding ideal section curve was studied. Then the Sigular Value Decomposition (SVD)-Iterative Closest Point (ICP) precision matching method was adopted to improve the matching precision. After that, the weight calculation method was applied to balance the profile errors among different section curves. Simulation work was performed to validate the proposed matching algorithm. Results shows that micrometer-order matching accuracy of the blade section curves could be obtained through the above-mentioned three matching steps.

As basis of the big diameter crystal development, the single crystal automatic growth is the most important technique for system standardization and mass production. In this article, author introduced a new useful way for the single crystal automatic growth of float zone. By setting the growth interval and controlling parameter, PLC controller could automatically control the single crystal growth when the single crystal’s diameter is greater than 50mm. This method applied to the machine system can greatly reduce the fault of manual operation as well as labor intensity. Also it improved the single crystal quality which increases the ability to develop big diameter single crystal in the future.

In aerospace engineering, seal is an important component of manned spacecraft life-support system. The pressurized tube sealing equipment is designed, and the experimental system of principle leak-rate of pressurized tube is built, and the experimental theory of the principle leak-rate of pressurized tube is carried out. The experimental results show that leak-rate of pressurized tube is related with the internal pressure of pressurized tube, and sealing ability can be adjusted by controlling the pressure in tube. And leak-rate of pressurized tube is involved with sealed pressure differential, and the bigger pressure differential is, the larger leak-rate becomes. And pressurized tube can fit for big structure transfiguration, which provides condition for lessening structural weight. And the pressurized tube can meet the demands of sealing of space station.

In order to improve the plasticity of the Al–Mg alloy, which fabricated by continuous casting and rolling, the alloy was heat treated at 370 °C, 400 °C, 430 °C and 460 °C for 2 hours and cooled with the furnace. The microstructure and mechanical properties of heat-treated Al–Mg alloy under different heat treatment temperatures were analyzed. The results show that the columnar grains begin to disappear at heat treatment temperature of 460 °C. The size of equiaxed grains begins to increase as the heat treatment temperature increases. The tensile strength of the alloy decreases with the increase of heat treatment temperature and the Brinell hardness increases when the heat treatment temperature is between 370-430 °C. At heat treatment of 430 °C, the elongation and the Brinell hardness of the alloy reached to 42.91% and 70.5 HB, respectively.

Electroplating was employed to prepare Cu films on Fe substrates and Ni substrates. The average internal stresses in Cu films were measured in situ by cantilever beam test. The distribution of the internal stresses in Cu films was investigated. The results show that the average internal stresses and the distributed internal stresses in Cu films decrease abruptly with the increase of film thickness when the films are thinner. The interfacial stresses in Cu films are very large and growth stresses are very small. The average internal stresses in Cu films, which were caused by the adjustment of the electron densities at either side of the interface, were calculated roughly using a modified Thomas–Feimi–Dirac electron theory. For the same substrate and the same film, the theoretical value of the average internal stress in film is about equal to the experimental value. It shows that the theoretical calculation model of internal stress is of accuracy.

Reliability design is a new design theory and design methods with the modern science and technology developed. Food waste processing equipment is a new and efficient equipment used for food waste recycling. This paper briefly describes the design of mechanical reliability, and by describing the characteristics of food waste, described in the food waste processing equipment design, the need for the use of reliability design. To provide some basic reliability analysis for the future design of equipment.

TiO₂ photocatalysts doped by Fe³⁺ with different contents were prepared by adsorption phase synthesis. The influence of Fe³⁺ doping with various concentrations on the crystallization of TiO₂ was explored by XRD. Then photodegradation experiments of methyl-orange were employed to evaluate the activity of these photocatalysts. The results indicated that the crystallization of TiO₂ was restricted after doping, due to replacement of Ti⁴⁺ in TiO₂ lattice structure by Fe³⁺ ions. And the restriction became stronger with doping concentration of Fe³⁺ ions increasing. Since radius of Fe³⁺ was close to Ti⁴⁺, the restriction of Fe³⁺ doping on crystallization of TiO₂ was so stronger that the photocatalytic activity of most TiO₂ doped with Fe³⁺ ions was lower than that of TiO₂ without doping.