Influence of the slip composition on the properties of tape-cast alumina substrates

• Published in: Ceramics international Vol. 31; no. 1; pp. 57 - 66
• Main Authors: Albano, Marı́a P., Garrido, Liliana B.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2005; Elsevier Science
• Subjects: A. Tape-casting; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; D. Al 2O 3; Electrotechnical and electronic ceramics; Exact sciences and technology; Green and sintered properties; Technical ceramics; A. Tape-casting; D. Al 2O 3; Green and sintered properties; Slip casting; Scanning electron microscopy; Green properties; Property composition relationship; Glycerol; Experimental study; Oxide ceramics; Substrate; Polyvinylalcohol; Additive; Sintering; Tape casting; Manufacturing; Aqueous solution; Alumina; Electroceramics; Rheological properties
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2004.03.035

Tape-casting process was used to produce alumina (Al 2O 3) substrates in an aqueous system with poly(vinylalcohol) (PVA) and glycerine as binder and plasticizer, respectively. Various compositions of Al 2O 3 slips were prepared by dispersing the powder in water with ammonium polyacrylate (NH 4PA), with subsequently additions of different amounts of PVA and glycerine. The influence of the slip composition on the rheological properties of the slips and the properties of the resultant green tapes were studied. In addition, the properties of the sintered tapes were investigated and related to those of the green tapes. PVA and glycerine did not affect the dispersion properties of the Al 2O 3 powder which were governed by the adsorbed NH 4PA. Glycerine additions enhanced the flexibility of the green tapes but also produced a decrease in the tensile strength and in the drying shrinkage. The increase in the PVA content increased the tensile strength but resulted in a markedly decrease in the green density of the tapes. The slip composition 5 wt.% PVA–5 wt.% glycerine produced green tapes with sufficient tensile strength and flexibility which had higher green and sintered density and lower sintering shrinkage. Thus, this composition was adequate for the production of Al 2O 3 substrates by the tape-casting process.