• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.135-142
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• 1996

Fly Ashes which are produced from coal-fired powder plants and classified as general waste can be used as raw materials for bricks and tiles because of their compositional similarity with clays. There was a limit of substituting fly ash for clay because plasticity decreased with increasing fly ash additions. Accordingly this study tried to suggest a feastibility of enhancing the substitution ratio by controlling the interfacial properties of fly ash. The slip with 1:1 volume ratio showed that best dispersive characteristics under the condition of pH 2 Filter pressed cakes made of pH 2 slips also showed better plastickity than those of untreated ones. of pH 2 Filter pressed cakes made of pH 2 also shwoed better plasticity than those of untreated ones.

• Journal of the Korean Ceramic Society
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• v.54 no.1
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• pp.55-60
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• 2017

An anorthite-based traditional ceramic was developed by adding secondary flux materials to a mixture of kaolin and $CaCO_3$ in order to minimize the deformation during the sintering process. Three flux materials, feldspar, talc, and frit, were evaluated by comparison with two commercial chinaware bodies. Anorthite body with glass frit exhibited poor firing shrinkage. Poor mechanical properties (modulus of rupture, MOR < 30 MPa) was observed for the bodies with feldspar. Another anorthite body was formulated with wollastonite as a Ca source. The fired body showed a MOR of 81 MPa and a shrinkage rate of 6% when wollastonite was added up to 50%. In the XRD analysis, the phase ratio between anorthite and quartz was the highest in the specimen with 50% wollastonite addition. Homogeneous and relatively small closed pores were observed in the microstructural analysis. These results suggest that a ceramic body formulated with 50% kaolin and 50% wollastonite can be fired at $1200^{\circ}C$ with a 6% firing shrinkage rate, giving rise to minimal sintering deformation.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.2
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• pp.117-122
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• 2006

This paper is to provide some of the analysis procedures of the FAD(Failure Assessment Diagram), which is applied th the safety test of the atomic pressure vessels and other structures. Harrison proposed R-6 Diagram, and Bloom developed the method of DPFAD(Deformation Plasticty Failure Assessment Diagram). Analysis of J-integration of the plastic materials give the failure test curve for the materials with serious work hardening effect. J value was obtained form both FEM(Finite Element Mothod) and the experiment using compact type specimen for J=JIC, and the results were compared. In this study, the results of analysis using DPFAD and the factors affecting DPFAD in Static fatigue and fracture were reviewed. It was shown that the concept of DPFAD can be applied to test the safety of the structures.