Hot Forging of Mullite‐Based Ceramics Prepared from Kaolin–Alumina

Abstract

Mullite‐based ceramics prepared from a mixture of kaolin and alumina were plastically deformed in uniaxial compression tests at high strain rates (= 10−2–10−3 s−1) at 1450° and 1500°C. Deformation occurred with barreling in tests that used SiC platens coated with h‐BN. This study shows that more‐suitable lubricants and molds (platens) must be found, to reduce friction between the mullite‐based ceramics and molds. However, this hot‐working method can be used to give a fine, textured surface to mullite‐based ceramic substrates for polycrystalline silicon thin‐film solar cells.