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Papier‐abgeleitete Steinzeugkeramiken: Eigenschaftsverbesserung durch Kalandern und Bestimmung des pyroplastischens Verformungsverhaltens
Author(s) -
Kluthe C.,
Kollenberg W.
Publication year - 2013
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/mawe.201300940
Subject(s) - calendering , ceramic , materials science , composite material , dwell time , deformation (meteorology) , amorphous solid , viscosity , filler (materials) , clinical psychology , chemistry , organic chemistry , medicine
Paper‐derived ceramics are a new approach to produce thin, lightweight ceramic structures. These ceramics are derived from preceramic papers produced in a paper technological process. The amount of inorganic filler (e. g. stoneware) in the paper is increased up to 85 wt‐%. By firing at high temperatures the cellulose fibres are pyrolized and the inorganic content is sintered. One part of the technological process to produce papers is calendering. A calender consists of two rolls, between which the paper is rolled under pressure. By calendering the paper thickness is reduced and the surface of the paper is improved. Different calender parameters (pressure and temperature) are applied to the preceramic paper and ceramic properties like strength, density and surface roughness are investigated. The strength of paper‐derived stoneware ceramics can be improved by 125% to over 185 MPa by optimizing the calender process. Additionally paper‐derived stoneware ceramics were fired at 1180°C, 1200°C and 1220°C for 1 and for 2 hours at different support distances (10–150 mm) in order to determine the dependence of pyroplastic deformation on support distance. The results show a linear increase between maximum deformation and support distance by 1 hour dwell and a polynomic at 2 hours dwell. Furthermore the Pyroplastic Index (PI) was evaluated according to recent literature. The Pyroplastic Index was correlated to the amorphous content of the differently fired samples. With longer dwell and/or higher temperature the content of amorphous phase increases which lowers the bulk viscosity and supports the pyroplastic deformation. These investigations should give a direction for using paper‐derived stoneware ceramics for special design applications. Paper‐derived ceramics can be systematically deformed in many possible ways to achieve specific shapes.