Vrstevnaté Al2O3/ZrO2 keramické kompozity připravené elektroforetickou depozicí

Laminated alumina/zirconia ceramic composites prepared by electrophoretic deposition

journal article - other

en

The electrophoretic deposition of alumina and zirconia powders from isopropanolic suspension in the presence of monochloroacetic acid was studied in the constant-current regime. The different levels of electric current during deposition from 250 microA to 48 mA were used. The green density of the deposit depends on the current density and then on the particle velocity during deposition, reaching values from 58% to 61% according to the electric current used. It was found that the lower the green density of the green deposit, the larger the pores. The low green density led to low final fired density and subsequently to the low Vickers hardness HV5 ranging from 2000 to 1650 depending on electric current used. Based on these findings microlaminates having various thickness ratios to achieve different residual stress levels were prepared consisting of alternating layers of alumina and zirconia.

V práci byla studována elektroforetická depozice v režimu konstantního proudu v prostředí isopropanolových suspenzí stabilizovaných kyselinou monochloroctovou a obsahující keramické prášky z oxidu hlinitého a oxidu zirkoničitého. Pro elektroforetickou depozici byly použity různé velikosti proudů od 250 mikroA do 48 mA. Hustota za syrova připravených depozitů byla závislá na proudové hustotě a také na rychlosti částic během depozice. Se změnou velikosti se hustota za syrova měnila z 58% na 61%. Bylo zjištěno, že při nižších hustotách za syrova depozity obsahují větší póry. Nižší hodnota hustoty za syrova vedla k nižší hodnotě hustotě po slinutí, což se projevilo na snížení hodnoty Vickersovy tvrdosti (z 2000HV5 na 1650HV5) v závisloti na použité velikosti elektrického proudu. Na základě těchto zjištění byl připraven mikrolaminát s alternujícími vrstvami Al2O3 a ZrO2, který měl proměnnou tloušťku vrstev k dosažení různé velikosti vnitřních napětí ve vrstvách.

The electrophoretic deposition of alumina and zirconia powders from isopropanolic suspension in the presence of monochloroacetic acid was studied in the constant-current regime. The different levels of electric current during deposition from 250 microA to 48 mA were used. The green density of the deposit depends on the current density and then on the particle velocity during deposition, reaching values from 58% to 61% according to the electric current used. It was found that the lower the green density of the green deposit, the larger the pores. The low green density led to low final fired density and subsequently to the low Vickers hardness HV5 ranging from 2000 to 1650 depending on electric current used. Based on these findings microlaminates having various thickness ratios to achieve different residual stress levels were prepared consisting of alternating layers of alumina and zirconia.

Elektroforetická depozice, Kompozity, Tvrdost, Al2O3, ZrO2

Electrophoretic deposition; Composites; Hardness; Al2O3; ZrO2

2012

01.07.2012

0955-2219

32

9

2053–2056

4