The Ni-coated TiH2composite powder was prepared by electroless plating and the concentration of reducing agent, reaction temperature, reaction time, PH value and so on were optimized by orthogonal experiment design. The Ni/TiH2composite powder morphology and composition was analyzed by scanning electron microscopy (SEM), Energy Dispersive spectroscopy (EDS), X-ray diffraction (XRD); the plated Ni layer growth mechanism was explored preliminary. The Optimization technical parameters: the plating temperature was 85, the pH value was 10 and the hydrazine concentration was 100ml/L. Complete coating and uniform thickness of the Ni layer with average coating thickness about 2.0μm was successfully prepared with the optimization technical parameters. The growth mechanism of the coating followed the Ostwald ripening mechanism. Compared the TiH2uncoated with Ni layers particles, the TiH2composite powder could efficiently delay the starting time of gas release by approximately 80s.

In the present work, Zn-1.0Cu-0.2Ti alloy was prepared by melt casting and extruding processes. High temperature creep property of the alloy was determined using electronic creep relaxation testing machine. Microstructures of the alloy before and after creep test were observed and its high temperature creep mechanism was discussed. The results show that the steady-state creep rate of the alloy increases with temperature and stress. The logarithm of steady-state creep rate (ln) shows a linearity relationship with the logarithm of the stress (lnσ) and reciprocal of temperature (1/T). The stress exponent and apparent activation energy for creep have been determined to be 5.10 and 83.7 kJ/mol, separately. The predominant mechanism is mainly self-diffusional creep. The second phases on the grain boundary can block the slip of grain boundary and dislocation motion which can improve creep resistance of the alloy.

The microstructure and oxidation behaviour of the pure AlON ceramics and 8 wt.% SiC-AlON composite were investigated at 700-1500?C. With increasing oxidation temperature, the surface morphology of two ceramics showed a change from acicular to flaky-like and then to granular features. With the addition of nanosized SiC particles, the oxidation resistance of the ceramics was remarkably enhanced above 1100?C. This is attributed to the formation of a dense oxide layer composed of Al2O3, SiO2 and mullite, which could cover the whole matrix and suppress further penetration of oxygen. Due to the dense oxide layer, the oxidation kinetics of the 8 wt.% SiC-AlON composites conformed to a parabolic law, while that of the pure AlON conformed to a linear law. After oxidation at 1500 ?C for 40 h, the weight gain of the 8 wt.% SiC-AlON composites was 3.07mg/cm2, which was only 22.5% of that of the pure AlON.

The effects of different solid-solution temperature (500, 600, 700, 800, 900°C) and holding time (0.5, 1, 1.5, 2h) on properties and microstructure of Cu-Zn-Al-Ni alloy were investigated experimentally. The result shows that the hardness of the alloy presents lowest at 700°C and then increases gradually as a function of temperature. It is also revealed that hardness has no relation with the holding time. Phase transition occurs when the temperature is 900°C, as a result of which increases the hardness of the alloy.