The Pressure Transmission Properties and its Application of Composite Powder between the Silica Powder and Hexagonal Boron Nitride

Abstract:

When filling liquid’s temperature is over 300 degrees centigrade, the internal high pressure forming process is easy to be decomposed and metamorphosed, therefore, as the pressure transmission medium, the important limited factor for the further development of the temperature state internal high pressure forming process is the heat-resistant limit. This paper analyzes the physical properties of the composite powder between micro silica and hexagonal boron nitride, and on the basis of it, discusses its pressure-transmitting properties under the static pressure condition. The researcher uses the pressing machine to force the press on different quality of the mixed powder in the different temperature, and measures the wall pressure distribution by using the high temperature resistant pressure sensor. The experimental results demonstrate that when the hexagonal boron nitride comes to 2 percents of the composite powder, the effect of the pressure transmission performance are the best, meanwhile it is not a significant factor for the temperature to influence the pressure transmission properties of the composite powder, and it will keep stable on the high temperature. In the 500 degrees centigrade, as the pressure transmission medium, the warm state internal high pressure forming research has been done through adding axial force and internal pressure to the 40Cr steel pipe fittings. The research results prove that the pressure transmission medium can not only overcome the traditional medium in high pressure forming filling liquid under high temperature, but also fully improve the plasticity deformation of metal workpieces. It helps to the bulging of complex, high hard metal pieces, and it is also helpful for simplified forming technology.

• Periodical: Advanced Materials Research (Volumes 472-475)
• Pages: 2885-2890
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.472-475.2885
• Online since: February 2012
• Authors: Cheng Zhu Jin, Ge Zhan
• Keywords: Hexagonal Boron Nitride (HBN), Internal High Pressure Forming, Pressure Transmission Properties, Silica Powder

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