Slip Casting of Carbon and SiC Ceramics

Beschreibung

In the present thesis, the near-net shaping of different non-oxide ceramic components by slip casting for two different application fields was investigated. The material properties and processing conditions were optimized for both materials, silicon carbide and sinterable carbon or PAM meso cokes, which are used in specific applications. The near-net shaping of components made of liquid phase sintered silicon carbide (LPS-SiC) was applied to the manufacture of mirror blanks for astronomical telescopes. As part of this work, a modified slip casting method was developed to form a thin-walled mirror blank with a diameter of 360 mm with a stiffening multi-rib structure on its backside. One of the most important advantages of this novel manufacturing concept introduced in this work is to achieve a slightly concave optical surface formation during liquid phase sintering. Different contraction behavior in final sintering between optical and ribbed surfaces leads to an advantageous and useful warping on flat surface. The slip casting method was successfully developed and proved to be more competitive and effective in comparison to conventional CIP- forming and subsequent green machining and pressureless sintering. Thanks to the near net shape manufacturing and relatively simple forming capability through the modified core casting method, the introduced liquid phase sintered silicon carbide based telescope mirror blank production in this work is a very cost effective approach. In best case, dense, pore free and fine grained material is obtained and additional CVD-coatings become dispensable.

Autor*in

Enbiya Türedi

Themen in »Slip Casting of Carbon and SiC Ceramics«

liquid-phase sintered SiC near net-shape manufacturing sinterable carbon precursor slip casting telescope mirror blank

Stimmen zu »Slip Casting of Carbon and SiC Ceramics«

Details

Link teilen