Effects of Pressure during Preform Densification on SiC/SiC Composites

Abstract

The nano-infiltration and transient eutectic-phase (NITE) method is one of the most attractive methods for fabrication of SiC and SiC/SiC composites. In the NITE method, preform densification is essential option for damage less near-net shaping technique. However, optimization of preform densification is insufficient yet. The objective of this study is to evaluate the effects of pressure during preform densification on SiC/SiC composites. The preform before preform densification has many pores in the inter-prepreg sheets. These pores were disappeared by preform densification. As the effects of pressure on preform, densification in the intra-fiber-bundle was improved due to increasing pressure. Flexural strength of the preforms with 1 MPa and 17 MPa indicated almost same value. The result suggested that increasing of pressure did not cause any change in fiber properties. In the effects of pressure on the composites, the composites with 17 MPa was exhibited improvement in bulk density and mechanical property, compared with that with 1 MPa.

Prevention of Catastrophic Volcanic Eruptions, Large Earthquakes underneath Big Cities, and Giant Earthquakes at Subduction Zones

“…magma chambers. These matters can be solved using a silica carbide composite [10] and an electro pulse drilling technique [11]. The eruption energy of Krakatoa in 1883 was estimated to be 200 MT (Megaton TNT (trinitrotoluene) equivalent) [12], namely 840 × 10 15 (J).…”

“…Problems in this system are corrosion of drilling rods and durability of drilling bits due to the high temperature and low pH near magma chambers. These matters can be solved using a silica carbide composite [10] and an electro pulse drilling technique [11].…”