Yttria stabilized zirconia formed by micro ceramic injection molding: Rheological properties and debinding effects on the sintered part

Farhana Mohd Foudzi, Norhamidi Muhamad, Abu Bakar Sulong, Hafizawati Zakaria

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Micro Ceramic Injection Molding (μCIM) is a near net-shape process to produce smaller and intricate parts at a competitive cost. The application of nano-sized ceramic powder in μCIM has the advantages of fine grain size growth and good surface finish. However, the nano size effect causes agglomeration and low powder loadings, which result in defects during the μCIM process and in the sintered components. This study extensively investigated the debinding and sintering of yttria-stabilized zirconia (YSZ), as well as its rheological properties, using polypropylene (PP) as the primary binder and palm stearin as the secondary binder. 50 nm Yttria stabilized zirconia (YSZ) powders were mixed with palm stearin and PP at a powder loading of 37-43 vol%. The results of rheological studies showed that the feedstock had a dilatant flow characteristic and a viscosity of around 10-40 Pa s. Feedstock with 38 vol% powder loading had the lowest activation energy of 9.48 kJ/mol. The green part of the injected feedstock had flexural strength ranging from 13 to16 MPa, within which the feedstock with 43 vol% powder loading had the highest green density. Solvent debinding was carried out at three temperatures (50, 60, and 70 °C) using heptane. A large porous region was clearly identified at 70 °C compared with 50 °C. A debinding split furnace with argon gas was used to remove PP at 450 °C for 4 h. The debound samples did not shrink when 94%-98% of the binder system was removed. All debound samples sintered at 1350 °C and 41 vol% had the highest mechanical properties with hardness of 900 HV and a flexural strength of 400 MPa.

Original languageEnglish
Pages (from-to)2665-2674
Number of pages10
JournalCeramics International
Volume39
Issue number3
DOIs
Publication statusPublished - Apr 2013

Fingerprint

Yttria stabilized zirconia
Injection molding
Powders
Feedstocks
Polypropylenes
Binders
Bending strength
Heptanes
Argon
Heptane
Furnaces
Sintering
Agglomeration
Activation energy
Gases
Hardness
Viscosity
Mechanical properties
Defects
Costs

Keywords

  • C. Mechanical properties
  • Micro ceramic injection molding (μCIM)
  • Nano sized zirconia
  • Rheological properties

ASJC Scopus subject areas

  • Ceramics and Composites
  • Process Chemistry and Technology
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

Yttria stabilized zirconia formed by micro ceramic injection molding : Rheological properties and debinding effects on the sintered part. / Mohd Foudzi, Farhana; Muhamad, Norhamidi; Sulong, Abu Bakar; Zakaria, Hafizawati.

In: Ceramics International, Vol. 39, No. 3, 04.2013, p. 2665-2674.

Research output: Contribution to journalArticle

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