FAST FIRING OF PORCELAIN BY VICTOR COLORADO A THESIS SUBMITTED TO THE FACULTY OF ALFRED UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN CERAMIC ENGINEERING ALFRED, NEW YORK DECEMBER, 2014 FAST FIRING OF PORCELAIN BY VICTOR COLORADO B. ENG. UNIVERSIDAD PONTIFICIA BOLIVARIANA (2007) Signature on file SIGNATURE OF AUTHOR Signature on file APPROVED BY________________________________________ WILLIAM M. CARTY, ADVISOR Signature on file __________________________________________ MATTHEW M. HALL, ADVISORY COMMITTEE Signature on file __________________________________________ DOREEN D. EDWARDS, ADVISORY COMMITTEE Signature on file __________________________________________ CHAIR, ORAL THESIS DEFENSE Signature on file ACCEPTED BY__________________________________________ DOREEN D. EDWARDS, DEAN KAZUO INAMORI SCHOOL OF ENGINEERING Alfred University theses are copyright protected and may be used for education or personal research only. Reproduction or distribution in part or whole is prohibited without written permission from the author. Signature page may be viewed at Scholes Library, New York State College of Ceramics, Alfred University, Alfred, New York. ACKNOWLEDGEMNTS First of all, I would like to thank the Corona Group and especially all the people of the company who has been supporting and trusted me on my commitment to face this challenge. Thanks to Luis Fernando Mejia, Diego Jaramillo, Laura Prada, Nelson López, Carlos Arismendi, Juan Antonio Montoya, Andrés Cadavid, Leonel Arrieta, Luis Miguel Posada and Felipe Giraldo. I would like to thank Dr. William Carty for his support, guidance, assistance and patience throughout the development of this project and for the interesting and helpful discussions we had. It has been a great honor to work with him, I feel really proud of be one of his students for what he represents for the academy and the ceramic industry in the world. I would also like to thank Hyojin Lee and Wirat Lerdprom for sharing their knowledge and for the helpful discussions about this research and porcelain in general. Thanks to all my friends in School: Diksha Kini, Ruifeng Ouyang, David Tseng, Kevin Keefe, and Dave Crenshaw. I would like to thank Dr. Doreen Edwards, Dr. Dawei Liu and Dr. Matthew Hall for the feedback and support as members of the thesis committee. Thanks to my family who made me what I am: my parents Javier Colorado and Alba Nelly Restrepo, my sister Vicky, my aunts, Sonia and Yolanda, my uncle John Jairo, and my grandparents Otilia and Juan. Thanks to my wife, Lina and my little girl, Luciana for being with me in the hard moments, they gave me the force to make it possible. iii TABLE OF CONTENTS Page Acknowledgments.............................................................................................................. iii Table of Contents ............................................................................................................... iv List of Tables ..................................................................................................................... vi List of Figures ................................................................................................................... vii Abstract ............................................................................................................................... x INTRODUCTION............................................................................................................. 1 LITERATURE REVIEW ................................................................................................ 3 A. Reactions occurring during firing of triaxial porcelain bodies ................................... 3 B. Factors influencing the maturing behavior of triaxial porcelains .............................. 5 C. Arrhenius model and activation energy of densification ............................................ 6 D. Fast Firing ........................................................................................................................ 10 EXPERIMENTAL PROCEDURE OUTLINE ............................................................ 13 A. Raw materials selection and chemical composition .................................................. 13 B. Green sample preparation .............................................................................................. 13 C. Firing ................................................................................................................................ 16 D. Characterization of the fired samples .......................................................................... 17 RESULTS AND DISCUSSION ..................................................................................... 20 A. Mullite formation............................................................................................................ 20 B. Quartz dissolution and glass chemistry ....................................................................... 22 1. Quartz dissolution and undissolved quartz......................................................... 22 2. Chemistry of the glass phase .............................................................................. 24 C. Densification ................................................................................................................... 28 1. Vitrification temperature .................................................................................... 28 2. Activation Energy for densification ................................................................... 33 D. Glass phase ...................................................................................................................... 35 1. Glass density ...................................................................................................... 36 2. Amount of Glass required for vitrification ......................................................... 38 SUMMARY AND CONCLUSIONS ............................................................................. 42 iv REFERENCES ................................................................................................................ 43 APPENDIX ...................................................................................................................... 47 A. Quantitative X-ray diffraction data .............................................................................. 48 B. Correlation matrix for the amount of mullite with the firing parameters and initial composition of the porcelain body ............................................................ 49 C. Correlation analysis for the model to predict the amount of undissolved quartz in the final body .................................................................................................. 49 D. Correlation analysis for the model to predict SiO in the glass phase ..................... 52 2 E. Correlation analysis for the model to predict glass amount necessary for vitrification ...................................................................................................................... 54 F. Correlation analysis for the model to predict vitrification temperature .................. 56 G. Hypothesis test for water absorption of 0.2% ............................................................. 58 v LIST OF TABLES Page Table I. Chemical Composition of the Raw Materials (Wt.%)......................................... 13 Table II. Composition of the Raw Materials in UMF Basis ............................................. 13 Table III. Chemical Composition of the Porcelain Bodies via ICP-ES (wt. %). .............. 14 Table IV. Composition of the Initial Porcelain Bodies in UMF Basis ............................. 15 Table V. Diffraction Peaks for Quantitative X-Ray Diffraction Analysis ........................ 19 Table VI. Regression Data from Arrhenius Plots for the Ten Experimental Compositions ................................................................................................. 34 Table VII. Comparison Between Glass Density Values from Different Studies .............. 38 Table VIII. Quantitative X-ray Diffraction Data for Vitrified Samples ........................... 48 vi LIST OF FIGURES Page Figure 1. Heat treatment chart for feldespatic whiteware bodies.24 Data were re-plotted for four different flux amounts as indicated. ................................... 8 Figure 2. Calculated activation energies for densification. Data re-plotted from Dannert. .......................................................................................................... 10 Figure 3. Experimental design for the porcelain compositions (three replicates of the central point). Compositions labeled in run order. .............................. 14 Figure 4. Set-up of the sample stage. The thermocouple for temperature control is located at the center of the stage, among the samples. ............................... 17 Figure 5. Relationship between Al O in glass phase (UMF) and the alkali 2 3 level in the body as (R O+RO) (mole %). ..................................................... 21 2 Figure 6. Comparison between measured mullite content (from quantitative X-ray diffraction and a glass density of 2.39 g/cm3) and calculated mullite level assuming an alumina saturation level of 1.16 moles of Al O 2 3 per mole of flux in the glass phase.. ............................................................... 22 Figure 7. Contour plot of the fraction of residual quartz (Q =Q /Q ) as a function UD F 0 of the firing parameters, temperature (°C) and dwell time (hour).. ............... 23 Figure 8. Comparison between calculated and measured undissolved quartz (Ratio Q /Q ) for different firing conditions (Dashed lines represent F 0 the 99% confidence interval). ........................................................................ 24 Figure 9. Silica UMF in the glass phase as a function of the amount available in the initial body. The 1:1 line represents the complete dissolution of the initial SiO in the glass phase. The dotted line represents the 2 amount of SiO dissolved from pure feldspar. ............................................... 25 2 vii Figure 10. Contour plot of the prediction model for silica level in glass phase as a function of the firing parameters (UMF basis). ...................................... 27 Figure 11. Comparison between calculated and measured SiO in Glass Phase for 2 different firing conditions. Dashed lines represent the 99% confidence interval. .......................................................................................................... 27 Figure 12. An example of shrinkage data with firing conditions. .................................... 28 Figure 13. An example of water absorption data with firing conditions. ......................... 30 Figure 14. An example of bulk density/specific gravity ratio with firing conditions. ...... 30 Figure 15. Maturing temperature for different dwell times as a function of the alkali level in the body (Data were obtained from the temperature gradient curves at 0.2% water absorption value). Values at 3.2% correspond to previous work. ........................................................................ 31 Figure 16. Maturing temperature for different alkali levels (mole %) as a function of dwell time. Values at 3.2% correspond to previous work. ........................ 32 Figure 17. Arrhenius plots for different alkali levels (mole %). The reaction velocity, k (hr-1), is calculated as the reciprocal of dwell time, t (hours)... .................. 34 Figure 18. Activation energy as a function of the alkali level of the body. Dashed lines represents the 99% confidence interval. ................................... 35 Figure 19. Density of the glass phase as a function of the total amount of silica and alumina in the glass........................................................................ 37 Figure 20. Density of the glass phase as a function of the flux content. The correlation coefficient, R2, is 0.78. ................................................................. 38 Figure 21. Amount of glass necessary for vitrification as a function of dwell time and flux level (mole %) when the body is fired at the proper maturation temperature. ................................................................................. 39 viii Figure 22. Comparison between calculated and measured amount of glass necessary for vitrification for different firing conditions and body compositions. The dashed lines represent the 99% confidence interval. ...... 40 Figure 23. Experimental data for amount of glass necessary for densification for a dwell time of one hour. The blue dot represents the value reported by Foster and the red dot by Lerdprom. .......................................... 41 Figure 24. Residual analysis for Undissolved Quartz in the initial porcelain body. ........ 51 Figure 25. Normal probability plot for residues (Undissolved Quartz model). ................ 51 Figure 26. Residues plot for SiO in the glass phase model ............................................. 53 2 Figure 27. Normal probability plot for residues (SiO in glass phase model) .................. 53 2 Figure 28. Residues plot for amount of glass necessary for vitrification model. ............. 55 Figure 29. Normal probability plot for residues (Amount of glass necessary for vitrification model). ....................................................................................... 55 Figure 30. Residues plot for vitrification temperature model. .......................................... 57 Figure 31. Normal probability plot for residues (Vitrification temperature model). ........ 57 Figure 32. Histogram for water absorption data with 95% confidence interval for the mean and H =0.2% (Std. Dev. of 0.113). ........................................... 59 0 ix