Gel Tape Casting of Ceramic Substrates

High thermal conductive Si3N4 is a promising candidate for producing high quality ceramic substrates used in vehicles. Although a lot of researches have been carried out on the tape casting of Si3N4, they were mainly restricted in fabricating thin films with a thickness less than 200μm which are not sufficient for producing substrate. With larger thickness, tapes tend to crack during drying. In this work, slurry of α-Si3N4 with Y2O3-MgO as additives was prepared using an azeotropic mixture of methylisobutylketone/methyehtylketone/cyclohexanone as media. To obtain thick green tapes, the amount of dispersant, binder and plasticizer in the slurry were optimized, and the effects of drying temperature on the cracking behavior of the tape were studied. By controlling the composition of the slurry and the drying conditions, thick green tapes with thicknesses up to 1.8mm were successfully fabricated, and Si3N4 substrates were produced after subsequent gas-pressing sintering, which were flat and had a relative density as high as 98.2%.

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Fabrication of Porous HA Ceramic Substrates by Freeze-Tape-Casting and Its Permeability Features

Springer Proceedings in Physics - Physics and Techniques of Ceramic and Polymeric Materials ◽

10.1007/978-981-13-5947-7_10 ◽

2019 ◽

pp. 85-91

Author(s):

Mengchen Mao ◽

Yufei Tang ◽

Rong Xu ◽

Kang Zhao ◽

Xinyi Zhao

Keyword(s):

Tape Casting ◽

Ceramic Substrates

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Processing of Aqueous Tape Casting of Glass-Ceramic in the SiO2-Al2O3-MgO-Li2O System with ZrO2 and B2O3 Addition

Materials Science Forum ◽

10.4028/www.scientific.net/msf.881.71 ◽

2016 ◽

Vol 881 ◽

pp. 71-76

Author(s):

Mariane Silva da Silveira ◽

Cristina Moniz Araujo Lopes ◽

Francisco C.L. Melo ◽

Rosa Maria Rocha

Keyword(s):

Thermal Treatment ◽

Glass Ceramic ◽

Glass Powder ◽

Tape Casting ◽

Glass Frit ◽

High Porosity ◽

Green Density ◽

Ceramic Substrates ◽

Casting Technique ◽

Burn Out

The aim of this work was to fabricate glass-ceramic substrates using aqueous tape casting technique of the parent glass powder in the SiO2-Al2O3-MgO-Li2O system with addition of ZrO2 and B2O3. The powder mixture was melted at 1650°C/1h and the obtained glass (frit) was milled and processed by tape casting in thin substrates with 700 μm thickness. Suspensions were prepared by aqueous medium and latex emulsion binder. Flexible green tapes with few defects were obtained using suspensions prepared with 7 and 10 wt% of binder in relation to glass powder. Substrates were submitted to burn out at 700 °C and thermal treatment at 950 oC/30min, 950 oC/4h and 1000 °C/1h. The green density of the substrates was around 1.55 g/cm3 and 2.10 g/cm3 after sintering/crystallization. Microstructure in all treatments showed high porosity. The major crystalline phases identified by XRD were Li0,6Al0,6Si2,4O6, ZrO2 and ZrSiO4.

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