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Composite mold samples used in squeeze casting was fabricated by plasma spraying with 5CrMnMo and 3YSZ, which was shown high bonding strength and good thermal shock resistance. The best parameters with transition coat were explored by mechanical analyses. As results, the transition layer structure made of 75 percent NiCoCrAlY powders showed bonding strength was higher to 34.35MPa and that thermal cycles were up to 46.8 times. The effect of the transition layer was analyzed by microstructures and the failure mechanism of the coating material with a transition layer was discussed. The conclusion was that the physical mismatch and thermodynamic mismatch between the matrix and ceramic layers were the main cause of the failure.

Mg-Zn-Zr-Y billets with different mass fraction of Y (wt%(Y)=0.2%、0.5%、1.0%、1.5%、2.0%) was prepared by permanent mold casting. The increase in Y content has shown grain refinement effects on the microstructure morphologies of Mg–Zn–Y–Zr alloys. When the content of Y achieves 1.0 wt%, the grain refinement effect of the Y is most obvious than any more contents of the Y content. In the test result of XRD, the type of precipitated phase in Mg-Zn-Zr-Y alloys is related to atomic ratio of Y/Zn. With content of Y increases, atomic ratio of Y/Zn increases,the precipitated phase in alloy is changed from Phase I to Phase W. Tensile strength and extension rate of alloy increase with the increasing of Y content; When Y content reaches 1.0%, mechanical property reaches maximum value.When content of Y exceeds 1.0%, with the increasing of Y content, mechanical property of alloy declines gradually.

In the present study, 7050 supplied in extruded state was heated to different temperatures below solidus or the semisolid state and microstructural evolution and coarsening were investigated. The results showed that complete recrystallisation only occurs after soaking for 5 minutes at 545°C, which is characterised by formation of a lot of fine equiaxed grains. RAP is suitable for fabricating high-quality semisolid billet of 7050 aluminum alloy with an average grain size ranging from 47.4 um to 70.5 um and a roundness ranging from 1.3 to 1.7. Grain growth occurs as the samples were soaked at 610°C and 615°Cfor prolonged soaking time. When the isothermal temperatures were 610°C and 615°C, the coarsening rate constants were 359.5μm3s-1 and 470.5μm3s-1, respectively, indicating an increase of coarsening rate constant (K) with the increasing isothermal temperature. Coarsening tends to occur via Ostwald ripening and coalescence. Ostwald ripening plays an important role during the whole coarsening process, but the grain coalescence only contributes to coarsening after soaking for 12 minutes. 625°C is an optimal temperature to keep cylinder shape of the sample due to collapse of the sample above this temperature, leading to difficult clamping.

As a new azide-free gas generating pyrotechnic composition, the performance of four kinds of 5-aminotetrazole nitrate (5-ATN) gas generating compositions were investigated by hygroscopicity, compatibility, impact sensitivity, heat of combustion and burning temperature measurement. The advantages of the gas generant using KNO3 as an oxidizing agent include small hygroscopicity, better compatibility, lower impact sensitivity and proper burning temperature. The degree of water sorption in the mixed system with Sr (NO3)2 was much higher than that with KNO3. The participation of CuO can reduce the hygroscopicity of the system with Sr (NO3)2. As the oxidizing agent and catalyst, CuO can also decrease the impact sensitivity, heat of combustion and burning temperature of both systems. 5-ATN gas generant provides fair compatibility using 5-ATN as separate system.

Pyrotechnical battery is successfully prepared, including an anode and cathode having pyrotechnic charges with an excess of fuel-anode and an excess of oxidation agent cathode (Zr, CuO and asbestos), the anode and cathode being separated by a separator formed from LiF, ZrO2 and fibrous sponge. Main performance indexes system of pyrotechnical battery is put forward and tested under the premise of appropriate mass and corresponding size, such as discharge voltage, discharge time, activation time, excitation time, internal resistance, combustion temperature and storage life. The results show that pyrotechnical battery of Zr/CuO system can basically meet application requirements. Activation time is usually about 0.2 s. Discharge voltage is about 1.96 V and the discharge time is up to 13.8 s or more. The internal resistance keeps a low fixed value (0.47Ω , for example). Combustion temperature of pyrotechnic composition can reach 1500.6 °C (the case temperature of battery is lower) to ensure that electrode and separator is adequately melted, consequently, the internal resistance is reduced, and achieving satisfactory discharge effect.