An Experimental Study On Preparing Ultra-fine-crystalline And Nanocrystalline Metal Using Electromagnetic Impulse High-pressure Rapid Solidification Method

Various present methods of preparation nanostructured materials are summarized and the theoretical analyses are made of preparation ultra-fine-crystalline and nanocrystalline metal using the rapid solidification method in this thesis. Experiment of preparation ultra-fine-crystalline and nanocrystalline metal was performed using self-developed electromagnetic impulse high-pressure rapid solidification method. The thickness, microstructure and hardness of the samples were measured using microscope, SEM and micro-hardness meter. The structures of the samples are ultra-fine-crystalline structures and their hardness are 1.5 to 1.8 times as the originals. The temperature field of rapid solidification, in which the two-dimension mathematical model was adopted, was analyzed using ANSYS FEA software. The calculation results of one-dimension and two-dimension temperature fields were compared. The results are very useful for the future rapid solidification experiment.Miao Li (power plant thermal power engineering) Directed by prof. Liu Zongde...