Vliv podmínek elektroforetické depozice na vlastnosti Al2O3-ZrO2 keramik

Effect of Electrophoretic Deposition Conditions on Final Properties of Alumina and Zirconia Deposits

conference proceedings

en

The electrophoretic deposition of alumina and zirconia powders from the isopropanolic suspension in the presence of monochloracetic acid was studied in the constant-current regime. The new method of deposition kinetics control, based on the direct weight measurement was developed enabling exact control of deposit weight. The different levels of electric current during deposition from 250 microA to 48 mA were used. The green density of deposit depends on the current density and then on the particle velocity during deposition and achieved thevalue from 58% to 61%, according to the electric current used. The lower green density of the deposit was, the larger pores were found in the deposit. The low green density led to low final fired density and subsequently to low Vickers hardness, changing from 2000 HV5 to 1650 HV5, depending on electric current used. Adopting these findings, the microlaminate consisting of alternating 75 layers of alumina and 75 layers of zirconia was prepared.

Byla studována elektroforetická depozice ze suspenzí složených z Al2O3 a ZrO2 keramických prášků a kyseliny monochloroctové z hlediska přesného popisu kinetiky procesu. Byla vyvinuta metoda založená na přímém vážení hmotnosti depozitu k přesnému popisu kinetiky depozice. Pro výrobu monolitické a kompozitní keramiky elektroforetickou depozicí byla použita metoda konstatního proudu v rozsahu 250 microA – 48 mA. Hustota vyžíhaných keramických depozitů zavisela na použité velikosti elektrického pole při depozici. Se snižující se velikostí proudu rostla hustota od 58% do 61% teoretické hodnoty. Nižší hustota byla způsobena přítomností velkých pórů v depozitu po vyžíhání. Tato skutečnost vedla také ke snížení výsledné tvrdosti keramiky po slinutí, shodně se změnou použitého proudu, z 2000 HV5 až na 1650 HV5. Díky předchozím zjištěním byl připraven keramický kompozit čítající 75 vrstev Al2O3 a 75 vrstev ZrO2.

The electrophoretic deposition of alumina and zirconia powders from the isopropanolic suspension in the presence of monochloracetic acid was studied in the constant-current regime. The new method of deposition kinetics control, based on the direct weight measurement was developed enabling exact control of deposit weight. The different levels of electric current during deposition from 250 microA to 48 mA were used. The green density of deposit depends on the current density and then on the particle velocity during deposition and achieved thevalue from 58% to 61%, according to the electric current used. The lower green density of the deposit was, the larger pores were found in the deposit. The low green density led to low final fired density and subsequently to low Vickers hardness, changing from 2000 HV5 to 1650 HV5, depending on electric current used. Adopting these findings, the microlaminate consisting of alternating 75 layers of alumina and 75 layers of zirconia was prepared.

elektroforetická depozice, kinetika depozice, keramické mikrolamináty

electrophoretic deposition, kinetics of deposition, ceramic micro-laminate

25.06.2009

978-83-60958-54-4

Proceedings of the 11th International conference and Exhibition of the European Ceramic Society

1072–1075

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