microCAD March 2007 INVESTIGATION AND DEVELOPMENT OF GLAZES AND COATINGS TO HIGH-TECH TECHNICAL CERAMICS Nikoletta PUSKÁS RIGÓNÉ University of Miskolc Department of Ceramics and Silicate Engineering

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Introduction – Aims  Development of quality of high-tech technical ceramics surfaces  Special glazes and coatings would be able to use  Comparing of glazes with different compositions  Find a way to develop better coatings for alumina than present used

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Materials – Compositions components m% base glaze 1 added material 2 Mg32 Al15,578 Si6412 K4,5- Ca132 Ba-5 Cr-1 Mg32 components m%substrate Mg2 Al78 Si13,5 K0,5 Ca6 1: Porcelain tableware glaze, 2: Extra hard, technical ceramic raw material

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Glazed samples  d = 40 mm, h = 8 mm  Green firing: 1100°C  7 type of glaze  Added material: 0, 5, 10, …, 30 %  Dipping technology  Firing: 1320°C

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Testing methods  Wear resistance examination  Microhardness measurement  Scratch test  Micro structure analysis (SEM) examination  Hot stage microscopy examination

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Wear resistance examination worn weight [%] added material concentration [%]  SiC powder  314 m wearing

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Microhardness measurement Thin coatingThin coating Microhardness measurementMicrohardness measurement To stay clear of cracksTo stay clear of cracks Loading: 0,5; 1; 2 NLoading: 0,5; 1; 2 N

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: added material concentration [%] microhardness [HVM] Microhardness measurement

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Scratch test

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Scratch test  0 % added material glaze scratch test diagram  Critical load: F n = 68N

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Scratch test  30 % added material glaze scratch test diagram  Critical load: F n = 106 N

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Micro structure analysis (SEM) 0 % added material 0 % added material 30 % added material 30 % added material boundary layer boundary layer 500 µm

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Micro structure analysis (SEM) 0 %substrate boundary layerglaze Mg2,51,612,99 Al77,5357,7815,85 Si13,5432,3463,34 K0,681,434,88 Ca5,746,8512,95 30 %substrate boundary layerglaze Mg2,221,910,38 Al77,416128,51 Si8,822751,17 K1,321,283,8 Ca6,616,7411,11 Ba2,811,383,73 Cr0,810,681, µm

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Hot stage microscopy examination  Melting  Wetting  Heating: about 20 °C/min  Ar atmosphere

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Hot stage microscopy examination – Melting  Photos made on different temperatures show the process of softening and melting

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Hot stage microscopy examination –Wetting  Possibilities: Wetting (  <90°) Non wetting (  >90°) Perfect wetting (  =0°)

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Hot stage microscopy examination Glaze with 0 % added material 21 and 1300 °C Glaze with 30 % added material 21 and 1300 °C Glaze with 5 % added material 21 and 1300 °C

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Other coatings  Silicon-carbide and chromium-carbide coatings on polished alumina  N=10000X 10 µm

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Other coatings  Chromium-carbide coating before and after 4 million cycle fatigue test  N=2500X 50 µm

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Conclusions  The critical loading force at scratch test developed up to 106 N from 68 N by adding extra hard technical ceramic raw material to glaze raw material  The melting temperature is more than 1300 °C with the 30 % added material  The wear resistance and microhardness are better as well than without added material  To stay clear of defects further examinations are going on  The non glaze coatings can develop very well the lifetime of the technical ceramics

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Acknowledgement  Department of Mechanical Technology  Department of Physical Metallurgy and Metalforming  Department of Chemistry

microCAD 2007, Miskolc, March 2007 Nikoletta Puskás Rigóné, Tel.: /1560, Fax.: Many thanks for your attention! Nikoletta PUSKÁS RIGÓNÉ