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Porcelain fused to metal (PFM) has received great attention over the last few years due to its importance in the dentistry. Kalsilite (K2O·Al2O3·SiO2) is a high thermal expansion porcelain, suitable for bonding to metals. However, kalsilite is a metastable phase which gets converted into crystalline leucite upon heating. In the current work feasibility of developing stable kalsilite phase, dispersion of MgF2 in it as an additive and using mechanochemical synthesis are studied. Micro fine dental material has been formulated by mixing prepared kalsilite with low temperature frit (LTF) in different ratio. The crystalline phases evolved in fired powders are characterized by powder X-ray diffraction (XRD) technique. Kalsilite with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion (CTE), flexural strength, apparent porosity (AP), bulk density (BD) and microstructure. Results indicate that MgF2 addition and high milling duration help in kalsilite stabilization. Temperature also plays an important role in this stabilization, and at 1100 ℃ single phase kalsilite formation is observed. Present outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.


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Role of MgF2 addition on high energy ball milled kalsilite: Implementation as dental porcelain with low temperature frit

Show Author's information Pattem Hemanth KUMARa( )Abhinav SRIVASTAVAaVijay KUMARaNandini JAISWALaPradeep KUMARbVinay Kumar SINGHa
Department of Ceramic Engineering, Indian Institute of Technology (BHU), Varanasi, India
Department of Chemical Engineering, Indian Institute of Technology (BHU), Varanasi, India

Abstract

Porcelain fused to metal (PFM) has received great attention over the last few years due to its importance in the dentistry. Kalsilite (K2O·Al2O3·SiO2) is a high thermal expansion porcelain, suitable for bonding to metals. However, kalsilite is a metastable phase which gets converted into crystalline leucite upon heating. In the current work feasibility of developing stable kalsilite phase, dispersion of MgF2 in it as an additive and using mechanochemical synthesis are studied. Micro fine dental material has been formulated by mixing prepared kalsilite with low temperature frit (LTF) in different ratio. The crystalline phases evolved in fired powders are characterized by powder X-ray diffraction (XRD) technique. Kalsilite with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion (CTE), flexural strength, apparent porosity (AP), bulk density (BD) and microstructure. Results indicate that MgF2 addition and high milling duration help in kalsilite stabilization. Temperature also plays an important role in this stabilization, and at 1100 ℃ single phase kalsilite formation is observed. Present outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.

Keywords:

kalsilite, porcelain fused to metal (PFM), dental ceramic, mechanochemical synthesis, thermal expansion, X-ray diffraction (XRD)
Received: 17 June 2014 Revised: 11 August 2014 Accepted: 18 August 2014 Published: 30 November 2014 Issue date: December 2014
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Publication history

Received: 17 June 2014
Revised: 11 August 2014
Accepted: 18 August 2014
Published: 30 November 2014
Issue date: December 2014

Copyright

© The author(s) 2014

Acknowledgements

The authors gratefully acknowledge the financial support of DST (TDT division, reference No. DST/SSTP/UP/197 (G) 2012), Ministry of Science & Technology, New Delhi, India.

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