Tensile experiment of AZ91D magnesium alloy was carried out and serrated flow was apparent throughout the deformation history. Dynamic strain aging (DSA) occurs when the AZ91D magnesium alloy treated by solid solution treatment has been deformed at a set range of strain rates (1.11×10-4 s-1 to1.67×10-3 s-1) and a certain range temperatures (248 K to 423 K). The critical plastic strain εc was observed to increase with increasing strain rates but decrease with increasing temperature. The diffusing activation energy of solute atoms during the DSA occurring in AZ91D magnesium alloy is 140.8 kJ/mol by calculating, which is correspondence match with the diffusing activation energy of Al solute atoms in Mg matrix. Therefore, the micro-mechanism of DSA in the alloy is believed that the Al atoms in solid solution gather around dislocations to form Cottrell solute atmospheres by vacant diffusion and then pin the moving dislocations.

Three groups of commercial 5052 Al alloy sheets were subjected to groove pressing (GP) at room temperature using parallel GP, 180° cross GP and 90° cross GP, respectively. Mechanical properties and fracture modes of as-annealed and GPed samples were investigated. The microhardness of the samples processed by parallel GP increases by a factor of about 1.6 compared to the as-annealed state, and that of the samples processed by cross GP is higher. The ultimate tensile strength (UTS) increases significantly after GP, while the elongation decreases. But they are strongly dependence on the number of GP passes and the pressing modes. Besides, fracture surface morphology demonstrates that the fracture mode is ductile even after four passes. With increasing the number of GP pass, the amount of small dimples increases, and the dimples become shallow and more uniform.

According to the working conditions of the nuclear power generator slot wedge and the principle of the heat treatment, CuCo2BeZr copper alloy was strengthened by a series of heating process test, finally acquired a good performance of the nuclear power slot wedge. The results show that, after the process of hot extrusion deformation of 85.5% and solution treatment at (940±10 )°C for 2h, then aging at 540 °C for 4h, the composition, microstructure, fracture morphology and tensile properties of CuCo2BeZr copper alloy, as the material of nuclear power generator, could meet the conditions of working continuously in high temperature enviroment.The research of CuCo2BeZr copper alloy provide scientific basis for analyzing the inner mechanism of the failure and predicting the working life of the nuclear power slot wedge material.

The thermally generated defects will lower the life time in bulk silicon and cause increasing in the leakage current of individual diodes in integrated circuits, that will finally cause the malfunction with advanced devices and IC chips. The removal characteristics of hillock defects on the single bare silicon wafer generated by the thermal process were experimentally analysed with respect to the chemical additives enhanced uniform chemical etching and mechanical abrasion of high pure nano sphere colloidal silica interplaying with the alkali based polishing slurry. During the polishing, it was found that the silicon surface contacted with high speed of rotated polishing pad under the down force pressure is chemically dissolved by the slurry containing FA/O organic polyamine(R(NH2)n) agent with adding proper proportional FA/O I non ions surfactant, which effectively lowered the surface strain of slurry contacted to the reactive surface of the wafer and slurry enhanced uniform chemical etch leading to the hillock region and no hillock region. However, by the process of chemical mechanical polishing，the results show it can eliminate the hillock defects on the surface of silicon wafer thoroughly with high removal rate, and achieve lower surface roughness than before process of polishing.

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