DENG Juanli 1,2, FAN Shangwu 2, CHENG Laifei 2, ZHANG Litong 2
(1.National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi'an Shanxi 710064; 2.School of Materials Science and Engineering, Chang'an University, Xi'an Shanxi 710072)
Abstract:A uniform mixture of silicon powder (granularity≤0.044 mm) and polyvinyl alcohol solution (PVA, 5wt %) in response to the proportion of 85: 15 has been prepared. After sieving, prilling and vibrating packing, the green compacts have been formed by cold isostatic pressing. The effects of the forming pressure, the pressure rising speed, and the dwell time on the strength and density of silicon green compacts were studied. The density and strength of the silicon green compacts were increased with the forming pressure increasing. When the pressure reached up to 275MPa, the density and strength gradually approached constant values, the density was about 1.61 g/cm3, and the strength was about 2.0MPa. The effect of the dwell time on the strength and density of silicon green compacts was little. The difference between the maximum and minimum density was only about 0.03g/cm3, and the changing rate was only about 1.96% with different dwell time.
Key words:cold isostatic pressing; process; green compact; performance